On 1/22/18 8:18 PM, Goldwyn Rodrigues wrote:

quoted

that their application was "already broken". I'd hate for a kernel
upgrade to break them.

I do wish we could make the change, and maybe we can. But it probably
needs some safe guard proc entry to toggle the behavior, something we
can drop in a few years when we're confident it won't break real
applications.

Assuming we call it /proc/sys/fs/dio_short_writes(better names/paths?),
should it be enabled or disabled by default?

I'd enable it by default, if not, you are never going to be able to
remove it because you'll have no confidence that anyone actually flipped
the switch and ran with it enabled. The point of having it there and on
by default would be that if something does break, people have the option
of turning it off and restoring the previous behavior, without having to
change the kernel.

-- 
Jens Axboe