On Fri, Jan 09, 2026 at 12:20:34PM +0100, Laurent Vivier wrote:
Refactor tcp_timer_ctl() to use the epoll_add() helper instead of manually constructing epoll_event and calling epoll_ctl() directly.
Also separate the error handling for timerfd_create() failure (-1) from fd overflow (> FD_REF_MAX) to provide more specific debug messages. The overflow case now logs the actual fd value, using flow_dbg_perror() in this case was not correct (no errno set).
Delay setting conn->timer until epoll_add() succeeds, removing redundant conn->timer = -1 assignments in error paths since the timer is already -1 when we enter this block.
Signed-off-by: Laurent Vivier
Reviewed-by: David Gibson
--- tcp.c | 32 +++++++++++++++++--------------- 1 file changed, 17 insertions(+), 15 deletions(-)
diff --git a/tcp.c b/tcp.c index e7fa85f346b2..58e5064db6b6 100644 --- a/tcp.c +++ b/tcp.c @@ -581,30 +581,32 @@ static void tcp_timer_ctl(const struct ctx *c, struct tcp_tap_conn *conn) return;
if (conn->timer == -1) { - union epoll_ref ref = { .type = EPOLL_TYPE_TCP_TIMER, - .flow = FLOW_IDX(conn) }; - struct epoll_event ev = { .data.u64 = ref.u64, - .events = EPOLLIN | EPOLLET }; - int epollfd = flow_epollfd(&conn->f); + union epoll_ref ref; int fd;
fd = timerfd_create(CLOCK_MONOTONIC, 0); - if (fd == -1 || fd > FD_REF_MAX) { + if (fd == -1) { flow_dbg_perror(conn, "failed to get timer"); - if (fd > -1) - close(fd); - conn->timer = -1; return; } - conn->timer = fd; - ref.fd = conn->timer; + if (fd > FD_REF_MAX) { + flow_dbg(conn, "timer fd overflow (%d > %d)", + fd, FD_REF_MAX); + close(fd); + return; + }
- if (epoll_ctl(epollfd, EPOLL_CTL_ADD, conn->timer, &ev)) { - flow_dbg_perror(conn, "failed to add timer"); - close(conn->timer); - conn->timer = -1; + ref.type = EPOLL_TYPE_TCP_TIMER; + ref.flow = FLOW_IDX(conn); + ref.fd = fd; + if (epoll_add(flow_epollfd(&conn->f), EPOLLIN | EPOLLET, + ref) < 0) { + flow_dbg(conn, "failed to add timer"); + close(fd); return; } + + conn->timer = fd; }
if (conn->flags & ACK_TO_TAP_DUE) { -- 2.52.0
-- David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson