generic_perform_write()/iomap_write_actor(): saner logics for short copy

if we run into a short copy and ->write_end() refuses to advance at all,
use the amount we'd managed to copy for the next iteration to handle.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2021-05-31 00:32:44 -04:00
commit bc1bb416bb
2 changed files with 19 additions and 30 deletions