[PATCH v3 0/2] poll_refs armoring

[Pavel Begunkov <asml.silence@gmail.com>]

Make poll_refs more robust and protected from overflows. The mechanism
description is in 2/2. 1/2 helps to make the second patch a little bit
cleaner by tunnelling all edge cases from arming to a tw.

A good way to test is to set IO_POLL_REF_BIAS to 0 and 1. 0 will make
the slowpath to be hit every single time, and 1 triggers it in case of
races.

v2: clear the retry flag before vfs_poll()
v3: fix not handling arm_poll* refs release edge cases with patch 1/2

Pavel Begunkov (2):
  io_uring: cmpxchg for poll arm refs release
  io_uring: make poll refs more robust

 io_uring/poll.c | 44 ++++++++++++++++++++++++++++++++++++++------
 1 file changed, 38 insertions(+), 6 deletions(-)

-- 
2.38.1