> BTW it seems that I made a little stronger claim than it is actually - > at least 3.18 works fine in all cases, so the issue was fixed a bit > earlier than in 4.2.
Ok, it turns out that the fix was brought by commit 447f05bb488bff4282088259b04f47f0f9f76760 Author: Akinobu Mita <akinobu.m...@gmail.com> Date: Thu Oct 9 15:26:58 2014 -0700 block_dev: implement readpages() to optimize sequential read This patch looks like a perfect candidate for affected stable queues, though actually it could be called 'a collateral fix'. Any objections against pinging stable/distro maintainers or better drop-in replacements are very welcomed. Thanks!