On Sun, Apr 25, 2021 at 04:57:45PM +0800, Ming Lei wrote: > Hi Guys, > > Revert 4 patches from Bart which try to fix request UAF issue related > with iterating over tagset wide requests, because: > > 1) request UAF caused by normal completion vs. async completion during > iterating can't be covered[1] > > 2) clearing ->rqs[] is added in fast path, which causes performance loss > by 1% according to Bart's test > > 3) Bart's approach is too complicated, and some changes aren't needed, > such as adding two versions of tagset iteration 4) synchronize_rcu() is added before shutting down one request queue, which may slow down reboot/poweroff very much on big systems with lots of HBAs in which lots of LUNs are attached. 5) freeing request pool in updating nr_requests isn't covered. Thanks, Ming
