From: Jens Axboe axboe@kernel.dk
Snipped from commit 9ca9fb24d5febccea354089c41f96a8ad0d853f8 upstream.
While reworking the poll hashing in the v6.0 kernel, we ended up grabbing the ctx->uring_lock in poll update/removal. This also fixed a bug with linked timeouts racing with timeout expiry and poll removal.
Bring back just the locking fix for that.
Reported-and-tested-by: Querijn Voet querijnqyn@gmail.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- io_uring/io_uring.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -5966,6 +5966,8 @@ static int io_poll_update(struct io_kioc struct io_kiocb *preq; int ret2, ret = 0;
+ io_ring_submit_lock(ctx, !(issue_flags & IO_URING_F_NONBLOCK)); + spin_lock(&ctx->completion_lock); preq = io_poll_find(ctx, req->poll_update.old_user_data, true); if (!preq || !io_poll_disarm(preq)) { @@ -5997,6 +5999,7 @@ out: req_set_fail(req); /* complete update request, we're done with it */ io_req_complete(req, ret); + io_ring_submit_unlock(ctx, !(issue_flags & IO_URING_F_NONBLOCK)); return 0; }