stdout can be redirected to a regular file. Regular files don't support epoll.
nspawn failed with: "Failed to register fds in epoll: Operation not permitted".
If stdout does not support epoll, assume it's always writable.
signal_ev.events = EPOLLIN;
signal_ev.data.fd = signal_fd;
signal_ev.events = EPOLLIN;
signal_ev.data.fd = signal_fd;
- if (epoll_ctl(ep, EPOLL_CTL_ADD, STDOUT_FILENO, &stdout_ev) < 0 ||
- epoll_ctl(ep, EPOLL_CTL_ADD, master, &master_ev) < 0 ||
+ if (epoll_ctl(ep, EPOLL_CTL_ADD, STDOUT_FILENO, &stdout_ev) < 0) {
+ if (errno != EPERM) {
+ log_error("Failed to register stdout in epoll: %m");
+ r = -errno;
+ goto finish;
+ }
+ /* stdout without epoll support. Likely redirected to regular file. */
+ stdout_writable = true;
+ }
+
+ if (epoll_ctl(ep, EPOLL_CTL_ADD, master, &master_ev) < 0 ||
epoll_ctl(ep, EPOLL_CTL_ADD, signal_fd, &signal_ev) < 0) {
log_error("Failed to register fds in epoll: %m");
r = -errno;
epoll_ctl(ep, EPOLL_CTL_ADD, signal_fd, &signal_ev) < 0) {
log_error("Failed to register fds in epoll: %m");
r = -errno;