[Samba] Direct I/O

[Jeremy Allison]

On Tue, Jan 25, 2022 at 09:09:36PM +0100, Ralph Boehme wrote:
>On 1/25/22 01:50, Christof Schmitt wrote:
>>FWIW, preadv2() has RWF_DSYNC and RWF_SYNC which provide O_DSYNC and
>>O_SYNC semantics per write. Maybe one of those aligns more closely with
>>WRITE_UNBUFFERED.
>
>perfect! Any takers? :)

Hmmm. How to add the in_flags field for the SMB_VFS_PREAD_SEND/SMB_VFS_PWRITE_SEND ?

Both take an fsp, so is this something we should be adding
to the files_struct as a structure element (or a one element
in the fsp_flags bitfield) or as a separate 'flags' parameter
to the VFS calls ?

Personally I prefer adding to the files_struct as that way it's
available to all handle-based VFS calls and we don't have
to change SMB_VFS_PREAD_SEND/SMB_VFS_PWRITE_SEND, and can
just make use of the feature inside vfs_default.c on
platforms that have it.