Subject: Re: letting userland issue FUA writes
To: Bill Studenmund <wrstuden@netbsd.org>
From: Pavel Cahyna <pavel.cahyna@st.mff.cuni.cz>
List: tech-kern
Date: 03/15/2006 17:23:51
On Tue, Mar 14, 2006 at 06:35:46PM -0800, Bill Studenmund wrote:
> I'm interested in adding infrastructure so that applications can issue
> writes that have the FUA (Force Unit Access) bit set. SCSI CDBs handle
> this, as do some RAID cards.
>
> The main question I have is what kind of user-level interfaces exist for
> this? I certainly could cook up a new system call, but I would much rather
> use prior art. My simplistic attempt at googling for this failed. Does
> anyone else have suggestions?
O_DSYNC is documented as: "each write will wait for the file data
to be committed to stable storage."
Is this semantics different from FUA?
Pavel Cahyna