IoCheckShareAccessEx function (wdm.h)
The IoCheckShareAccessEx routine is called by file system drivers (FSDs) or other highest-level drivers to check whether shared access to a file object is permitted.
Syntax
NTSTATUS IoCheckShareAccessEx(
[in] ACCESS_MASK DesiredAccess,
[in] ULONG DesiredShareAccess,
[in, out] PFILE_OBJECT FileObject,
[in, out] PSHARE_ACCESS ShareAccess,
[in] BOOLEAN Update,
[in] PBOOLEAN WritePermission
);
Parameters
[in] DesiredAccess
Specifies an ACCESS_MASK value that indicates the desired type of access to the given file object.
[in] DesiredShareAccess
Specifies the desired type of shared access to the file object for the current open request. The value of this parameter is usually the same as the ShareAccess parameter that is passed to the file system or highest-level driver by the I/O manager when the open request was made. This value can be zero, or any combination of the following:
FILE_SHARE_READ
FILE_SHARE_WRITE
FILE_SHARE_DELETE
[in, out] FileObject
A pointer to the file object for which to check access for the current open request.
[in, out] ShareAccess
A pointer to the common share-access data structure that is associated with FileObject. Drivers should treat this structure as opaque.
[in] Update
Specifies whether to update the share-access status for FileObject. A Boolean value of TRUE means this routine will update the share access information for the file object if the open request is permitted.
[in] WritePermission
Specifies whether the share access has write permission. This value is TRUE if the share has write permission; otherwise, FALSE. If the value is FALSE and the share access has write permission and the caller attempts to take exclusive read access, the write permission is downgraded to FILE_SHARE_READ. This value is NULL if a write permission check is not done on the share access.
Return value
The IoCheckShareAccessEx routine returns STATUS_SUCCESS if the requester's access to the file object is compatible with the way in which it is currently open. If the request is denied because of a sharing violation, then STATUS_SHARING_VIOLATION is returned.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Available in Windows 7 and later versions of Windows. |
| Target Platform | Universal |
| Header | wdm.h |
| Library | Ntoskrnl.lib |