Hi,

While staring at epoll, I noticed ep_events_available() looks wrong. I
wrote a small program to confirm, and yes it is definitely wrong.

This series adds a reproducer to kselftest, and fix the bug.

v3: rebase onto vfs tree
v2: Switch to seqlock solution

Nam Cao (2):
  selftests/eventpoll: Add test for multiple waiters
  eventpoll: Fix epoll_wait() report false negative

 fs/eventpoll.c                                | 20 ++++++++-
 .../filesystems/epoll/epoll_wakeup_test.c     | 45 +++++++++++++++++++
 2 files changed, 64 insertions(+), 1 deletion(-)

-- 
2.47.3

On Tue, 02 Jun 2026 19:51:44 +0200, Nam Cao wrote:
> While staring at epoll, I noticed ep_events_available() looks wrong. I
> wrote a small program to confirm, and yes it is definitely wrong.
> 
> This series adds a reproducer to kselftest, and fix the bug.
> 
> v3: rebase onto vfs tree
> v2: Switch to seqlock solution
> 
> [...]

Applied to the vfs-7.2.eventpoll branch of the vfs/vfs.git tree.
Patches in the vfs-7.2.eventpoll branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs-7.2.eventpoll

[1/2] selftests/eventpoll: Add test for multiple waiters
      https://git.kernel.org/vfs/vfs/c/827382c088e9
[2/2] eventpoll: Fix epoll_wait() report false negative
      https://git.kernel.org/vfs/vfs/c/0c4aefe3c2d0