FSH_DEVIOCTL - Send IOCTL request to device driver
This function sends an IOCTL request to a device driver.
int far pascal FSH_DEVIOCTL(flag, hDev, sfn, cat, func, pParm, cbParm, pData,
unsigned short flag;
unsigned long hDev;
unsigned short sfn;
unsigned short cat;
unsigned short func;
char far * pParm;
unsigned short cbParm;
char far * pData;
unsigned short cbData;
flag indicates whether the FSD initiated the call or not.
IOflag == 0x0000 indicates that the FSD is just passing user pointers on
to the helper.
IOflag == 0x0001 indicates that the FSD initiated the DevIOCtl call as
opposed to passing a DevIOCtl that it had received.
All other bits are reserved.
hDev is the device handle obtained from VPB
sfn is the system file number from open instance that caused the
This field should be passed unchanged from the sfi_selfsfn field. If no
open instance corresponds to this call, this field should be set to
cat is the category of IOCTL to perform.
func is the function within the category of IOCTL.
pParm is the long address to the parameter area.
cbParm is the length of the parameter area.
pData is the long address to the data area.
cbData is the length of the data area.
If no error is detected, a zero error code is returned. If an error is
detected, one of the following error codes is returned:
indicates the function supplied is incompatible with the category and
device handle supplied.
indicates the category supplied is incompatible with the function and
device handle supplied.
oDevice driver error code
The only category currently supported for this call is 8, which is for the
logical disk. FSDs call FSH_DEVIOCTL to control device driver operation
independently from I/O operations. This is typically in filtering
DosDevIOCtl requests when passing the request on to the device driver.
An FSD needs to be careful of pointers to buffers that are passed to it
from FS_IOCTL, and what it passes to FSH_DEVIOCTL. It is possible that
such pointers may be real mode pointers if the call was made from the DOS
mode. In any case, the FSD must indicate whether it initiated the DevIOCtl
call, in which case the kernel can assume that the pointers are all
protect mode pointers, or if it is passing user pointers on to the
FSH_DEVIOCTL call, in which case the mode of the pointers will depend on
whether this is the DOS mode or not. An important thing to note is that
the FSD must not mix user pointers with its own pointers when using this
FSH_DEVIOCTL may block.
Note: OS/2 does not validate input parameters. Therefore, an FSD should
call FSH_PROBEBUF where appropriate.
Created using Inf-PHP v.2 (c) 2003 Yuri Prokushev
Created using Inf-HTML v.0.9b (c) 1995 Peter Childs