On Tue, Jun 13, 2017 at 06:24:32AM -0400, Jeff Layton wrote:

That's definitely what I want for the endgame here. My plan was to add
this flag for now, and then eventually reverse it (or drop it) once all
or most filesystems are converted.

We can do it that way from the get-go if you like. It'll mean tossing in
 a patch add this flag to all filesystems that have an fsync operation
and that use the pagecache, and then gradually remove it from them as we
convert them.

Which method do you prefer?

Please do it from the get-go.  Or in fact figure out if we can get
away without it entirely.  Moving the error reporting into ->fsync
should help greatly with that, so what's missing after that?