From: Jens Axboe axboe@kernel.dk
[ Upstream commit 56952e91acc93ed624fe9da840900defb75f1323 ]
If we're doing polled IO and end up having requests being submitted async, then completions can come in while we're waiting for refs to drop. We need to reap these manually, as nobody else will be looking for them.
Break the wait into 1/20th of a second time waits, and check for done poll completions if we time out. Otherwise we can have done poll completions sitting in ctx->poll_list, which needs us to reap them but we're just waiting for them.
Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/io_uring.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
--- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -7404,7 +7404,17 @@ static void io_ring_exit_work(struct wor if (ctx->rings) io_cqring_overflow_flush(ctx, true);
- wait_for_completion(&ctx->completions[0]); + /* + * If we're doing polled IO and end up having requests being + * submitted async (out-of-line), then completions can come in while + * we're waiting for refs to drop. We need to reap these manually, + * as nobody else will be looking for them. + */ + while (!wait_for_completion_timeout(&ctx->completions[0], HZ/20)) { + io_iopoll_reap_events(ctx); + if (ctx->rings) + io_cqring_overflow_flush(ctx, true); + } io_ring_ctx_free(ctx); }