RX_CONTEXT structure (rxcontx.h)
The RX_CONTEXT structure encapsulates an IRP for use by RDBSS, network mini-redirectors, and the file system. It describes an IRP while it is being processed by a network mini-redirector and contains state information that allows global resources to be released as the IRP is completed.
Syntax
typedef struct _RX_CONTEXT {
NODE_TYPE_CODE NodeTypeCode;
NODE_BYTE_SIZE NodeByteSize;
__volatile ULONG ReferenceCount;
LIST_ENTRY ContextListEntry;
UCHAR MajorFunction;
UCHAR MinorFunction;
BOOLEAN PendingReturned;
BOOLEAN PostRequest;
PDEVICE_OBJECT RealDevice;
PIRP CurrentIrp;
PIO_STACK_LOCATION CurrentIrpSp;
PMRX_FCB pFcb;
PMRX_FOBX pFobx;
PMRX_SRV_OPEN pRelevantSrvOpen;
PNON_PAGED_FCB NonPagedFcb;
PRDBSS_DEVICE_OBJECT RxDeviceObject;
PETHREAD OriginalThread;
PETHREAD LastExecutionThread;
__volatile PVOID LockManagerContext;
PVOID RdbssDbgExtension;
RX_SCAVENGER_ENTRY ScavengerEntry;
ULONG SerialNumber;
ULONG FobxSerialNumber;
ULONG Flags;
BOOLEAN FcbResourceAcquired;
BOOLEAN FcbPagingIoResourceAcquired;
UCHAR MustSucceedDescriptorNumber;
union {
struct {
union {
NTSTATUS StoredStatus;
PVOID StoredStatusAlignment;
};
ULONG_PTR InformationToReturn;
};
IO_STATUS_BLOCK IoStatusBlock;
};
union {
ULONGLONG ForceLonglongAligmentDummyField;
PVOID MRxContext[MRX_CONTEXT_FIELD_COUNT];
};
PVOID WriteOnlyOpenRetryContext;
PMRX_CALLDOWN MRxCancelRoutine;
PRX_DISPATCH ResumeRoutine;
RX_WORK_QUEUE_ITEM WorkQueueItem;
LIST_ENTRY OverflowListEntry;
KEVENT SyncEvent;
LIST_ENTRY BlockedOperations;
PFAST_MUTEX BlockedOpsMutex;
LIST_ENTRY RxContextSerializationQLinks;
union {
struct {
union {
FS_INFORMATION_CLASS FsInformationClass;
FILE_INFORMATION_CLASS FileInformationClass;
};
PVOID Buffer;
union {
LONG Length;
LONG LengthRemaining;
};
BOOLEAN ReplaceIfExists;
BOOLEAN AdvanceOnly;
} Info;
struct {
UNICODE_STRING SuppliedPathName;
NET_ROOT_TYPE NetRootType;
PIO_SECURITY_CONTEXT pSecurityContext;
} PrefixClaim;
};
union {
struct {
NT_CREATE_PARAMETERS NtCreateParameters;
ULONG ReturnedCreateInformation;
PWCH CanonicalNameBuffer;
PRX_PREFIX_ENTRY NetNamePrefixEntry;
PMRX_SRV_CALL pSrvCall;
PMRX_NET_ROOT pNetRoot;
PMRX_V_NET_ROOT pVNetRoot;
PVOID EaBuffer;
ULONG EaLength;
ULONG SdLength;
ULONG PipeType;
ULONG PipeReadMode;
ULONG PipeCompletionMode;
USHORT Flags;
NET_ROOT_TYPE Type;
UCHAR RdrFlags;
BOOLEAN FcbAcquired;
BOOLEAN TryForScavengingOnSharingViolation;
BOOLEAN ScavengingAlreadyTried;
BOOLEAN ThisIsATreeConnectOpen;
BOOLEAN TreeConnectOpenDeferred;
UNICODE_STRING TransportName;
UNICODE_STRING UserName;
UNICODE_STRING Password;
UNICODE_STRING UserDomainName;
} Create;
struct {
ULONG FileIndex;
BOOLEAN RestartScan;
BOOLEAN ReturnSingleEntry;
BOOLEAN IndexSpecified;
BOOLEAN InitialQuery;
} QueryDirectory;
struct {
PMRX_V_NET_ROOT pVNetRoot;
} NotifyChangeDirectory;
struct {
PUCHAR UserEaList;
ULONG UserEaListLength;
ULONG UserEaIndex;
BOOLEAN RestartScan;
BOOLEAN ReturnSingleEntry;
BOOLEAN IndexSpecified;
} QueryEa;
struct {
SECURITY_INFORMATION SecurityInformation;
ULONG Length;
} QuerySecurity;
struct {
SECURITY_INFORMATION SecurityInformation;
PSECURITY_DESCRIPTOR SecurityDescriptor;
} SetSecurity;
struct {
ULONG Length;
PSID StartSid;
PFILE_GET_QUOTA_INFORMATION SidList;
ULONG SidListLength;
BOOLEAN RestartScan;
BOOLEAN ReturnSingleEntry;
BOOLEAN IndexSpecified;
} QueryQuota;
struct {
ULONG Length;
} SetQuota;
struct {
PV_NET_ROOT VNetRoot;
PSRV_CALL SrvCall;
PNET_ROOT NetRoot;
} DosVolumeFunction;
struct {
ULONG FlagsForLowIo;
LOWIO_CONTEXT LowIoContext;
};
};
PWCH AlsoCanonicalNameBuffer;
PUNICODE_STRING LoudCompletionString;
__volatile LONG AcquireReleaseFcbTrackerX;
__volatile ULONG TrackerHistoryPointer;
RX_FCBTRACKER_CALLINFO TrackerHistory[RDBSS_TRACKER_HISTORY_SIZE];
ULONG ShadowCritOwner;
} RX_CONTEXT, *PRX_CONTEXT;
Members
NodeTypeCode
The unique node type used for an RX_CONTEXT structure. RDBSS sets this member to RDBSS_NTC_RX_CONTEXT when an RX_CONTEXT is initialized in RxInitializeContext. If a network mini-redirector driver initializes an RX_CONTEXT structure using some other method, this member must be set.
RDBSS defines this member as part of a standard header for all structures used by RDBSS.
All of the major structure types used by RDBSS have a unique two-byte node type code defined in nodetype.h that can be used for debugging. These major structure types include the following:
NodeByteSize
The size, in bytes, of this structure. RDBSS sets this member to sizeof( RX_CONTEXT) when an RX_CONTEXT is initialized in the RxInitializeContext routine. If a network mini-redirector driver initializes an RX_CONTEXT structure using some other method, this member must be set.
RDBSS defines this member as part of a standard header for all structures used by RDBSS.
ReferenceCount
The reference count for this structure after it is allocated. RDBSS sets this member to 1 when an RX_CONTEXT is allocated and initialized in the RxInitializeContext routine. If a network mini-redirector driver initializes an RX_CONTEXT structure using some other method, this member must be set.
RDBSS defines this member as part of a standard header for all structures used by RDBSS.
ContextListEntry
The list entry to connect this RX_CONTEXT to the list of active RX_CONTEXTS.
MajorFunction
The major function for the IRP encapsulated by this RX_CONTEXT.
MinorFunction
The minor function for the IRP encapsulated by this RX_CONTEXT.
PendingReturned
If set to TRUE, this specifies that RDBSS or a driver has marked the IRP pending. Each IoCompletion routine should check the value of this flag. If the flag is TRUE, and if the IoCompletion routine will not return STATUS_MORE_PROCESSING_REQUIRED, the routine should call IoMarkIrpPending to propagate the pending status to drivers above it in the device stack. This member is similar to the same field in the IRP.
RDBSS always sets this member to TRUE before calling the network mini-redirector driver.
PostRequest
If set to TRUE, this indicates if the associated request is to be posted to a RDBSS worker thread. A network mini-redirector can set this member to TRUE to indicate that it wants to post this request to the file system process (FSP).
RealDevice
A pointer to the device object for the target network mini-redirector driver. RDBSS sets this member to the device object for the network mini-redirector driver when an RX_CONTEXT is allocated in the RxInitializeContext routine. This member is copied from the FileObject->DeviceObject member from the IRP stack. The device object for the network mini-redirector is also stored in the RxDeviceObject structure member.
The RealDevice member is not currently used by RDBSS, but can be used by network mini-redirectors.
CurrentIrp
A pointer to the originating IRP. This member should not be used by a network mini-redirector driver.
CurrentIrpSp
A pointer to the IRP stack location.
pFcb
A pointer to the associated file control block (FCB) for this IRP.
pFobx
A pointer to the associated file object extension (FOBX) for this IRP.
pRelevantSrvOpen
A pointer to the associated server open(SRV_OPEN) for this IRP.
NonPagedFcb
A pointer to the associated non-paged file control block (FCB) for this IRP.
RxDeviceObject
A pointer to the RDBSS_DEVICE_OBJECT for the target network mini-redirector driver which is required for worker queue algorithms. RDBSS sets this member to the RDBSS_DEVICE_OBJECT for the network mini-redirector when an RX_CONTEXT is initialized in the RxInitializeContext routine. The RxDeviceObject structure includes a DeviceObject member that contains the device object for the network mini-redirector driver which is the same as the RealDevice member of the RX_CONTEXT.
OriginalThread
A pointer to the original thread in which the request was initiated.
LastExecutionThread
A pointer to the last thread in which some processing associated with the RX_CONTEXT was done if the thread was posted to the file system process.
LockManagerContext
A pointer to the lock manager context. This member is reserved for internal use.
RdbssDbgExtension
A pointer to the context given to RDBSS for debugging information. This member is reserved for internal use.
ScavengerEntry
A pointer to the list of items to be scavenged. This member is reserved for internal use.
SerialNumber
The serial number for this RX_CONTEXT structure. Every structure initialized by RDBSS has a serial number assigned when the structure is first initialized. This serial number is a number that is incremented by one before the value is set. RDBSS sets this member when an RX_CONTEXT is initialized in the RxInitializeContext routine. RDBSS
FobxSerialNumber
The serial number for the associated FOBX structure. Every structure initialized by RDBSS has a serial number assigned when the structure is first initialized. This member can be used by network mini-redirectors to see if multiple calls are part of the same larger operation and are therefore more cacheable.
Flags
A bitmask of flags for this RX_CONTEXT structure.
FcbResourceAcquired
If set to TRUE, this member specifies that the FCB resource has been acquired for this operation. The FCB resource is one of the locking mechanisms associated with an operation on an FCB.
FcbPagingIoResourceAcquired
If set to TRUE, this member specifies that the FCB paging I/O resource has been acquired for this operation. The FCB paging I/O resource is one of the locking mechanisms associated with a paging I/O operation on an FCB.
MustSucceedDescriptorNumber
A member initially set to zero in the RxCreateRxContext routine. This member is not otherwise used by RDBSS, but it may be used by network mini-redirectors.
StoredStatus
A member of an unnamed union used to return status information by a network mini-redirector driver for low I/O operations. RDBSS also sets this value based on the status returned by the MRxQueryFileInfo routine when the file query operation is not understood by RDBSS.
StoredStatusAlignment
A member of an unnamed union used to force proper alignment on the StoredStatus member.
InformationToReturn
A member of an unnamed union used to return status information by a network mini-redirector driver for some low I/O (read, write, FSCTL, etc.) and MrxQueryXXX operations.
The unique node type used for an RX_CONTEXT structure. All of the major structure types (RX_CONTEXT, SRV_CALL, NET_ROOT, V_NET_ROOT, SRV_OPEN, FCB, and FOBX, for example) used by RDBSS have a unique two-byte node type code defined in the nodetype.h include file which can be used for debugging. RDBSS sets this member to RDBSS_NTC_RX_CONTEXT when an RX_CONTEXT is initialized in the RxInitializeContext routine. If a network mini-redirector driver initializes an RX_CONTEXT structure using some other method, this member must be set.
RDBSS defines this member as part of a standard header for all structures used by RDBSS.
IoStatusBlock
The I/O status block use by a network mini-redirector to return status information. The IoStatusBlock member is a member of an unnamed union used for returning status information.
ForceLonglongAligmentDummyField
A member of an unnamed union used to force proper alignment on the MRxContext[MRX_CONTEXT_FIELD_COUNT] member.
MRxContext[MRX_CONTEXT_FIELD_COUNT]
WriteOnlyOpenRetryContext
A pointer that can be used to store some state for the network mini-redirector. This member is not used by RDBSS, but it can be used by a network mini-redirector driver to indicate that a file is cached on a write-only handle.
MRxCancelRoutine
A pointer to the cancellation routine that can be set by a network mini-redirector driver.
ResumeRoutine
This member is reserved for internal use.
WorkQueueItem
A pointer to a work queue item that can be used by a network mini-redirector driver while processing the RX_CONTEXT.
OverflowListEntry
A pointer to the list head of operations that are to be released on completion. This member is reserved for internal use.
SyncEvent
A pointer to a kernel EVENT that can be used by a network mini-redirector driver to wait while processing the RX_CONTEXT.
BlockedOperations
A pointer to the list head of blocked operations that are to be released on completion. This member is reserved for internal use.
BlockedOpsMutex
A pointer to a mutex that controls serialization of the blocked operations. This member is reserved for internal use.
RxContextSerializationQLinks
A pointer to the list entry used to serialize pipe operations on a per-file-object basis. This member is reserved for internal use.
Info
A structure member of an unnamed union used for the following routines:
- MRxQueryDirectory
- MRxQueryFileInfo
- MRxQueryVolumeInfo
- MRxSetFileInfo
- MRxSetFileInfoAtCleanup
- MRxSetVolumeInfo
RDBSS passes information in the Info structure member to the network mini-redirector and the network mini-redirector returns information to RDBSS in the Info structure member.
Info.FsInformationClass
A member of an unnamed union used by RDBSS to pass the type of FS_INFORMATION_CLASS that is requested to the network mini-redirector driver. RDBSS passes information in the FsInformationClass member when calling MrxQueryVolumeInfo and MrxSetVolumeInfo.
Info.FileInformationClass
A member of an unnamed union used by RDBSS to indicate the type of FILE_INFORMATION_CLASS request sent to the network mini-redirector driver. RDBSS passes information in the FileInformationClass member when calling MrxQueryDirectory, MrxQueryFileInfo, and MrxSetFileInfo.
Info.Buffer
A buffer used to pass data from RDBSS to the network mini-redirector driver and receive responses from the network mini-redirector driver by RDBSS. The Buffer member is used in the MrxQueryDirectory, MrxQueryFileInfo, MrxQueryVolumeInfo, MrxSetFileInfo, MRxSetFileInfoAtCleanup, and MrxSetVolumeInfo routines.
Info.Length
A member of an unnamed union used to pass the length of the Buffer member from RDBSS to the network mini-redirector driver. The Length member is used in the MrxQueryDirectory, MrxQueryFileInfo, MrxQueryVolumeInfo, MrxSetFileInfo, MRxSetFileInfoAtCleanup, and MrxSetVolumeInfo routines.
Info.LengthRemaining
A member of an unnamed union used to pass the length of information returned in the Buffer member from the network mini-redirector driver to RDBSS. The LengthRemaining member is used in the MrxQueryDirectory, MrxQueryFileInfo, MrxQueryVolumeInfo, MrxSetFileInfo, MRxSetFileInfoAtCleanup, and MrxSetVolumeInfo routines.
Info.ReplaceIfExists
A Boolean value that indicates if an existing file should be replaced during a rename operation. The ReplaceIfExists member is used in the MrxSetFileInfo routine.
Info.AdvanceOnly
This member is reserved for internal use.
PrefixClaim
A structure member of an unnamed union used for prefix resolution requests sent from the Multiple UNC Provider (MUP). A prefix claim results from an IRP_MJ_DEVICE_CONTROL request from MUP to RDBSS for IOCTL_REDIR_QUERY_PATH or IOCTL_REDIR_QUERY_PATH_EX. RDBSS passes information in the PrefixClaim structure to the network mini-redirector and the network mini-redirector returns information to RDBSS in the PrefixClaim structure.
PrefixClaim.SuppliedPathName
A non-NULL terminated Unicode string specifying the UNC path on which to perform the prefix resolution.
PrefixClaim.NetRootType
The type of the NET_ROOT requested. This member is not currently used. RDBSS deduces the type of the NET_ROOT from the SuppliedPathName member.
PrefixClaim.pSecurityContext
A pointer to the security context passed in from the request from MUP.
This member is not currently used. The security context is passed in the Create.NtCreateParameters.SecurityContext member of the RX_CONTEXT, not in this member.
Create
A structure member of an unnamed union used for handling IRP_MJ_CREATE requests. This member is used for handling file open requests that result in calls to the MRxCreate routine. This member is also used for prefix resolution requests. RDBSS passes information in the Create structure member to the network mini-redirector and the network mini-redirector returns information to RDBSS in the Create structure member.
Create.NtCreateParameters
The create parameters passed to the user-mode NtCreatefile routine. RDBSS sets the members of the NtCreateParameters structure based on the Parameters.Create members of the IRP.
Create.ReturnedCreateInformation
A value set by the network mini-redirector on completion of the MRxCreate call.
Create.CanonicalNameBuffer
A pointer to the Unicode string representing the name of physical file to open if the canonical name is larger than the available buffer.
Create.NetNamePrefixEntry
A pointer to the NetName table prefix entry. This member is reserved for internal use.
Create.pSrvCall
A pointer to the associated SRV_CALL structure.
Create.pNetRoot
A pointer to the associated NET_ROOT structure.
Create.pVNetRoot
A pointer to the associated V_NET_ROOT structure.
Create.EaBuffer
A pointer to the extended attributes buffer. This member is optional.
Create.EaLength
The length of the extended attributes buffer, EaBuffer.
Create.SdLength
The length of the security descriptor. RDBSS sets this based on the value of the Parameters.Create.SecurityContext member of the IRP. If the SdLength member is nonzero, the security descriptor is passed in the Info.Buffer member to the network mini-redirector.
Create.PipeType
The type of a pipe. This member is reserved for internal use.
Create.PipeReadMode
The read mode for a pipe. This member is reserved for internal use.
Create.PipeCompletionMode
The completion mode for a pipe. This member is reserved for internal use.
Create.Flags
The create flags
Create.Type
The type of the associated NET_ROOT structure.
Create.RdrFlags
Create.FcbAcquired
This member is reserved for internal use.
Create.TryForScavengingOnSharingViolation
This member is reserved for internal use.
Create.ScavengingAlreadyTried
This member is reserved for internal use.
Create.ThisIsATreeConnectOpen
A Boolean value that indicates if this call is a tree connect open request with the FILE_CREATE_TREE_CONNECTION option set in the IrpSp->Parameters.Create.Options member.
Create.TreeConnectOpenDeferred
A Boolean value that indicates the network mini-redirector can choose to defer the tree connect open request.
Create.TransportName
A Unicode string that represents the transport name. This member is set from the tree connect open parameters.
Create.UserName
A Unicode string that represents the user name responsible for the request. This member is set from the tree connect open parameters.
Create.Password
A Unicode string that contains the password for this UserName used for authentication and authorization. This member is set from the tree connect open parameters.
Create.UserDomainName
A Unicode string that contains the domain name for this UserName.
QueryDirectory
A structure member of an unnamed union used for handling IRP_MJ_DIRECTORY_CONTROL requests. This member is used for handling query directory requests that result in calls to the MrxQueryDirectory routine. RDBSS passes information in the QueryDirectory structure member to the network mini-redirector.
QueryDirectory.FileIndex
The Index of the entry at which to begin scanning the directory if the IndexSpecified member is set to TRUE. This parameter is set to the IrpSp->Parameters.QueryDirectory.FileIndex member.
QueryDirectory.RestartScan
A Boolean value when set to TRUE indicates that the scan is to start at the first entry in the directory. When this value is set to FALSE, the scan is resuming from a previous call. This parameter must be set to TRUE when calling for the first time. This parameter is set to TRUE if IrpSp->Flags has the SL_RESTART_SCAN bit on.
QueryDirectory.ReturnSingleEntry
A Boolean value set to TRUE indicates that only a single entry should be returned. If this parameter is TRUE, MrxQueryDirectory should return only the first entry that is found. This parameter is set to TRUE if IrpSp->Flags has the SL_RETURN_SINGLE_ENTRY bit on.
QueryDirectory.IndexSpecified
A Boolean value when set to TRUE indicates to begin the scan at the entry in the directory whose index is given by the FileIndex member. This parameter is set to TRUE if IrpSp->Flags has the SL_INDEX_SPECIFIED bit on.
QueryDirectory.InitialQuery
A Boolean value that is set to TRUE when the query is not a wild card query (".", for example). This member is set to TRUE if the UnicodeQueryTemplate.Buffer member of the associated FOBX is NULL and the Flags member of the FOBX does not have the FOBX_FLAG_MATCH_ALL bit on. For a wild card query (".", for example), RDBSS will set the UnicodeQueryTemplate.Buffer member of the associated FOBX to the wild card query passed.
NotifyChangeDirectory
A structure member of an unnamed union used for handling IRP_MJ_DIRECTORY_CONTROL requests with a minor function of IRP_MN_NOTIFY_CHANGE_DIRECTORY. This member is used for handling directory change requests that result in calls to the MRxLowIOSubmit[LOWIO_OP_NOTIFY_CHANGE_DIRECTORY] routine. RDBSS passes information in the NotifyChangeDirectory structure member and the pLowIoContext->ParamsFor.NotifyChangeDirectory structure to the network mini-redirector.
NotifyChangeDirectory.pVNetRoot
A pointer to the V_NET_ROOT structure associated with the directory. This parameter is set to the IrpSp->FileObject->FsContext member or the IrpSp->FileObject->FsContext2 member depending on the node type.
QueryEa
A structure member of an unnamed union used for handling IRP_MJ_QUERY_EA requests. This member is used for handling extended attribute query requests that result in calls to the MRxQueryEaInfo routine. RDBSS passes information in the QueryEa structure member to the network mini-redirector.
QueryEa.UserEaList
A pointer to a caller-supplied input buffer containing a FILE_GET_EA_INFORMATION structure specifying the extended attributes to be queried. This parameter is set to IrpSp->Parameters.QueryEa.EaList.
QueryEa.UserEaListLength
The length, in bytes, of the buffer pointed to by UserEaList member. This parameter is set to IrpSp->Parameters.QueryEa.EaListLength.
QueryEa.UserEaIndex
The Index of the entry at which to begin scanning the extended-attribute list. This parameter should be ignored if the IndexSpecified member is not set to TRUE or if QueryEaList member points to a nonempty list. This parameter is set to IrpSp->Parameters.QueryEa.EaIndex.
QueryEa.RestartScan
A Boolean value when set to TRUE indicates that the query is to start at the first extended attribute entry. When this value is set to FALSE, the scan is resuming from a previous call. This parameter must be set to TRUE when calling for the first time. This parameter is set to TRUE if IrpSp->Flags has the SL_RESTART_SCAN bit on.
QueryEa.ReturnSingleEntry
A Boolean value when set to TRUE indicates that only a single entry should be returned. If this parameter is TRUE, MrxQueryEaInfo should return only the first entry that is found. This parameter is set to TRUE if IrpSp->Flags has the SL_RETURN_SINGLE_ENTRY bit on.
QueryEa.IndexSpecified
A Boolean value when set to TRUE indicates to begin the scan at the entry in the extended attributes whose index is given by the UserEaIndex member. This parameter is set to TRUE if IrpSp->Flags has the SL_INDEX_SPECIFIED bit on.
QuerySecurity
A structure member of an unnamed union used for handling IRP_MJ_QUERY_SECURITY requests. This member is used for handling query security requests that result in calls to the MRxQuerySdInfo routine. RDBSS passes information in the QuerySecurity structure member to the network mini-redirector.
QuerySecurity.SecurityInformation
A pointer to a caller-supplied input buffer containing a SECURITY_INFORMATION structure specifying the operation to be queried. This parameter is set to IrpSp->Parameters.QuerySecurity.SecurityInformation.
QuerySecurity.Length
The length, in bytes, of the buffer pointed to by SecurityInformation member. This parameter is set to IrpSp->Parameters.QuerySecurity.Length.
SetSecurity
A structure member of an unnamed union used for handling IRP_MJ_SET_SECURITY requests. This member is used for handling query security requests that result in calls to the MRxSetSdInfo routine. RDBSS passes information in the SetSecurity structure member to the network mini-redirector.
SetSecurity.SecurityInformation
A pointer to a caller-supplied input buffer containing a SECURITY_INFORMATION structure that specifies which security information is to be set in the security descriptor. This parameter is set to IrpSp->Parameters.SetSecurity.SecurityInformation.
SetSecurity.SecurityDescriptor
A pointer to a SECURITY_DESCRIPTOR structure that contains the values of the security information to be assigned to the object. This parameter is set to IrpSp->Parameters.SetSecurity.SecurityDescriptor.
QueryQuota
A structure member of an unnamed union used for handling IRP_MJ_QUERY_QUOTA requests. This member is used for handling query security requests that result in calls to the MRxQueryQuotaInfo routine. RDBSS passes information in the QueryQuota structure member to the network mini-redirector.
QueryQuota.Length
The length, in bytes, of the buffer pointed to by StartSid member. This parameter is set to IrpSp->Parameters.QueryQuota.Length.
QueryQuota.StartSid
An optional pointer to a SID that indicates that the returned information is to start with an entry other than the first entry. This parameter is ignored if the SidList member is specified. This parameter is set to IrpSp->Parameters.QueryQuota.StartSid.
QueryQuota.SidList
An optional pointer to a list of SIDs whose quota information is to be returned. Each entry in the list is a FILE_GET_QUOTA_INFORMATION structure. This parameter is set to IrpSp->Parameters.QueryQuota.SidList.
QueryQuota.SidListLength
The length, in bytes, of the list of SIDs in the SidList member, if one is specified. This parameter is set to IrpSp->Parameters.QueryQuota.SidListLength.
QueryQuota.RestartScan
A Boolean value when set to TRUE indicates that the query is to start at the first entry. When this value is set to FALSE, the scan is resuming from a previous call. This parameter must be set to TRUE when calling for the first time. This parameter is set to TRUE if IrpSp->Flagshas the SL_RESTART_SCAN bit on.
QueryQuota.ReturnSingleEntry
A Boolean value when set to TRUE indicates that only a single entry should be returned. If this parameter is TRUE, MrxQueryQuotaInfo should return only the first entry that is found. This parameter is set to TRUE if IrpSp->Flags has the SL_RETURN_SINGLE_ENTRY bit on.
QueryQuota.IndexSpecified
A Boolean value when set to TRUE indicates to begin the scan at the entry in the list whose index is given by the StartSid member. This parameter is set to TRUE if IrpSp->Flags has the SL_INDEX_SPECIFIED bit on.
SetQuota
A structure member of an unnamed union used for handling IRP_MJ_SET_QUOTA requests. This structure is not currently used by RDBSS.
SetQuota.Length
An unused member of the SetQuota structure.
DosVolumeFunction
A structure member of an unnamed union. This structure is not currently used by RDBSS.
DosVolumeFunction.VNetRoot
An unused member of the DosVolumeFunction structure.
DosVolumeFunction.SrvCall
An unused member of the DosVolumeFunction structure.
DosVolumeFunction.NetRoot
An unused member of the DosVolumeFunction structure.
FlagsForLowIo
A set of RX_CONTENT_CREATE_FLAGS set by RDBSS and passed to low I/O operations sent to the network mini-redirector. FlagsForLowIo is a member of an unnamed structure used for low I/O requests to the network mini-redirector.
LowIoContext
A pointer to a LOWIO_CONTEXT structure passed to the network mini-redirector. LowIoContext is a member of unnamed structure used for low I/O requests sent to the network mini-redirector.
AlsoCanonicalNameBuffer
A pointer to the Unicode string representing the name of physical file to open if the canonical name is larger than the available buffer.
LoudCompletionString
An unused member of the RX_CONTEXT structure.
AcquireReleaseFcbTrackerX
Reserved for system use.
TrackerHistoryPointer
Reserved for system use.
TrackerHistory[RDBSS_TRACKER_HISTORY_SIZE]
Reserved for system use.
ShadowCritOwner
Reserved for system use.
Remarks
The RX_CONTEXT structure is one of the fundamental data structures used by RDBSS and network mini-redirectors to manage an I/O request packet (IRP). It encapsulates an IRP for use by RDBSS, network mini-redirectors, and the file system. An RX_CONTEXT structure includes a pointer to a single IRP and all of the context required to process the IRP.
An RX_CONTEXT structure is sometimes referred to as an IRP Context or RxContext in the WDK header files and other resources used for developing network mini-redirector drivers.
The RX_CONTEXT is a data structure to which additional information provided by the various network mini redirectors is attached. The RX_CONTEXT includes fields for over allocating the size of each RX_CONTEXT structure by a pre-specified amount for each network mini redirector, which is then reserved for use by the mini redirector. This approach consists of allocating a pre-specified area, which is the same for all network mini redirectors as part of each RX_CONTEXT. This is an unformatted area on top of which any desired structure can be imposed by the various network mini redirectors. Developers of network mini-redirector drivers should try and define the associated private context to fit into this pre-specified area defined in the RX_CONTEXT data structure. Network mini-redirector drivers that violate this rule will incur a significant performance penalty.
Many RDBSS routines and routines exported by a network mini-redirector make reference to RX_CONTEXT structures in either the initiating thread or in some other thread used by the routine. Thus, allocated RX_CONTEXT structures are reference counted to manage their use for asynchronous operations. When the reference count goes to zero, the allocated RX_CONTEXT structure can be finalized and released on the last dereference operation.
RDBSS provides a number of routines that are used to manipulate an RX_CONTEXT and the associated IRP. These routines are used to allocate, initialize, and delete an RX_CONTEXT. These routines are also used to complete the IRP associated with an RX_CONTEXT and set up a cancel routine for an RX_CONTEXT.
Requirements
| Requirement | Value |
|---|---|
| Header | rxcontx.h (include Rx.h, Rxcontx.h) |