Re: i_version, NFSv4 change attribute

["J. Bruce Fields" <bfields@fieldses.org>]

On Mon, Nov 23, 2009 at 11:44:45AM -0500, J. Bruce Fields wrote:
> If the side we want to optimize is the modifications, I wonder if we
> could do all the i_version increments on *read* of i_version?:
> 
> 	- writes (and other inode modifications) set an "i_version_dirty"
> 	  flag.
> 	- reads of i_version clear the i_version_dirty flag, increment
> 	  i_version, and return the result.
> 
> As long as the reader sees i_version_flag set only after it sees the
> write that caused it, I think it all works?

Except I'm a little confused about how i_version behaves (and should
behave) on reboot.  Assuming it's currently correct, I think it's enough
to also increment i_version as above when writing out the inode.

--b.