Re: let FS force FDIRECT [PATCH]

[Emmanuel Dreyfus <manu%netbsd.org@localhost>]

On Tue, Aug 12, 2014 at 09:33:26AM +0000, Emmanuel Dreyfus wrote:
> A less intrusive way is to cheat and just add a VV_IO_DIRECT flag for struct
> vnode's v_vflag. puffs_vnoop_open() could set it without any VFS interface
> modification, and VOP_READ() could use it to force IO_DIRECT. 
> 
> The later is cheating because we cannot support the situation where the
> filesystem tells us to use direct IO on a file descriptor and not on another
> one. But I am not sure it could make sense from a FS point of view.

We can cheat that way and keep the flag in struct puffs_node, leaving 
struct vnode untouched. This patch does that:
http://ftp.espci.fr/shadow/manu/iodirect.patch

Questions: 

1) Is the feature interesting beyond PUFFS? If not, then the patch above
will probably be fine.

2) Should I bump libpuffs minor in such a situation?

-- 
Emmanuel Dreyfus
manu%netbsd.org@localhost