On Tue, Apr 21, 2026 at 5:31 AM Zhenzhong Wu <[email protected]> wrote: > > Inside migrate_dance(), add epoll checks around shutdown() to > verify that the target listener is not ready before shutdown() > and becomes ready immediately after shutdown() triggers migration. > > Cover TCP_ESTABLISHED and TCP_SYN_RECV. Exclude TCP_NEW_SYN_RECV > as it depends on later handshake completion. > > Suggested-by: Kuniyuki Iwashima <[email protected]> > Signed-off-by: Zhenzhong Wu <[email protected]> > --- > .../bpf/prog_tests/migrate_reuseport.c | 46 ++++++++++++++++--- > 1 file changed, 40 insertions(+), 6 deletions(-) > > diff --git a/tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c > b/tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c > index 653b0a20f..6180a79a7 100644 > --- a/tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c > +++ b/tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c > @@ -7,24 +7,29 @@ > * 3. call listen() for 1 server socket. (migration target) > * 4. update a map to migrate all child sockets > * to the last server socket (migrate_map[cookie] = 4) > - * 5. call shutdown() for first 4 server sockets > + * 5. for TCP_ESTABLISHED and TCP_SYN_RECV cases, verify via epoll > + * that the last server socket is not ready before migration. > + * 6. call shutdown() for first 4 server sockets > * and migrate the requests in the accept queue > * to the last server socket. > - * 6. call listen() for the second server socket. > - * 7. call shutdown() for the last server > + * 7. for TCP_ESTABLISHED and TCP_SYN_RECV cases, verify via epoll > + * that the last server socket is ready after migration. > + * 8. call listen() for the second server socket. > + * 9. call shutdown() for the last server > * and migrate the requests in the accept queue > * to the second server socket. > - * 8. call listen() for the last server. > - * 9. call shutdown() for the second server > + * 10. call listen() for the last server. > + * 11. call shutdown() for the second server > * and migrate the requests in the accept queue > * to the last server socket. > - * 10. call accept() for the last server socket. > + * 12. call accept() for the last server socket. > * > * Author: Kuniyuki Iwashima <[email protected]> > */ > > #include <bpf/bpf.h> > #include <bpf/libbpf.h> > +#include <sys/epoll.h> > > #include "test_progs.h" > #include "test_migrate_reuseport.skel.h" > @@ -350,8 +355,28 @@ static int update_maps(struct > migrate_reuseport_test_case *test_case, > > static int migrate_dance(struct migrate_reuseport_test_case *test_case) > { > + struct epoll_event ev = { > + .events = EPOLLIN, > + }; > + int epoll = -1, nfds; > int i, err; > > + if (test_case->state != BPF_TCP_NEW_SYN_RECV) { > + epoll = epoll_create1(0); > + if (!ASSERT_NEQ(epoll, -1, "epoll_create1")) > + return -1; > + > + ev.data.fd = test_case->servers[MIGRATED_TO]; > + if (!ASSERT_OK(epoll_ctl(epoll, EPOLL_CTL_ADD, > + test_case->servers[MIGRATED_TO], > &ev), > + "epoll_ctl")) > + goto close_epoll; > + > + nfds = epoll_wait(epoll, &ev, 1, 0); > + if (!ASSERT_EQ(nfds, 0, "epoll_wait 1")) > + goto close_epoll; > + } > + > /* Migrate TCP_ESTABLISHED and TCP_SYN_RECV requests > * to the last listener based on eBPF. > */
Sorry I forgot to update return -1 to goto close_epoll when shutdown() fails. Otherwise looks good. Reviewed-by: Kuniyuki Iwashima <[email protected]> > @@ -365,6 +390,15 @@ static int migrate_dance(struct > migrate_reuseport_test_case *test_case) > if (test_case->state == BPF_TCP_NEW_SYN_RECV) > return 0; > > + nfds = epoll_wait(epoll, &ev, 1, 0); > + if (!ASSERT_EQ(nfds, 1, "epoll_wait 2")) { > +close_epoll: > + close(epoll); > + return -1; > + } > + > + close(epoll); > + > /* Note that we use the second listener instead of the > * first one here. > * > -- > 2.43.0 >
