IOCTL_EHSTOR_DEVICE_SET_QUEUE_STATE IOCTL (ehstorioctl.h)

Article
02/22/2024

The IOCTL_EHSTOR_DEVICE_SET_QUEUE_STATE request is sent by silo drivers and applications to change the state of a storage device queue. IO requests in the storage device queue are held when the device is temporarily unauthorized.

Major code

IRP_MJ_DEVICE_CONTROL

Input buffer

The input buffer at Irp->AssociatedIrp.SystemBuffer contains an ACT_QUEUE_STATE structure. ACT_QUEUE_STATE is declared in ehstorioctl.h as the following.

typedef struct tagACT_QUEUE_STATE
{
    BOOLEAN fFrozen;
} ACT_QUEUE_STATE;

Input buffer length

The length of an ACT_QUEUE_STATE structure.

Output buffer

None.

Output buffer length

None.

Status block

One of the following values can be returned in the Status field.

Status Value	Description
STATUS_SUCCESS	The queue state was changed successfully.
STATUS_INVALID_BUFFER_SIZE	The input buffer length is too small.
STATUS_ACCESS_DENIED	The IOCTL request was not issued by a silo driver.

Remarks

Silo drivers or applications can freeze the storage device IO request queue if temporary unauthorization is needed. Normally, temporary unauthorization occurs during low power states or when a policy requires locking of Enhanced Storage devices such as a locked user session. In such a case, it is preferable to put pending IO requests on hold rather than fail the IO requests and cause data loss.

To prevent abuse of the IOCTL_EHSTOR_DEVICE_SET_QUEUE_STATE request by applications, only a driver can issue this IOCTL. If sent from a user mode application, this request will fail with STATUS_ACCESS_DENIED.

Requirements

Requirement	Value
Minimum supported client	Available starting with Windows 8
Header	ehstorioctl.h (include EhStorIoctl.h)