Well, it wasn't that hard to fix just this issue. I tested the
following two patches, and verified that splice-in and splice-out now
always return full counts, even if pages are invalidated during the
splicing.
The ClearPageUptodate() thing in 1/2 needs a bit of careful attention
from VM hackers (Hugh and Nick added to CC).
I still see small issues with generic_file_splice_read() (more in a
separate email) and I don't quite see how this async thing is going to
work out, but that's another story.
Thanks,
Miklos
--