From 5b5e6deabb8b76bcd691c4e40429bd8478a49a32 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Wed, 27 Dec 2017 18:22:31 +0100 Subject: [PATCH] bus: touch() the AF_UNIX sockets we listen() on after the fact We'd like to use inotify to get notified when AF_UNIX sockets become connectable. That happens at the moment of listen(), but this is doesn't necessarily create in a watchable inotify event. Hence, let's synthesize one whenever we generically create a socket, or when we know we created it for a D-Bus server. Ideally we wouldn't have to do this, and the kernel would generate an event anyway for this. Doing this explicitly isn't too bad however, as the event is still nicely associated with the AF_UNIX socket node, and we generate all D-Bus sockets in our code hence it's safe. --- src/basic/socket-label.c | 5 +++++ src/core/dbus.c | 4 ++++ 2 files changed, 9 insertions(+) diff --git a/src/basic/socket-label.c b/src/basic/socket-label.c index e67a5cf..97f3ebe 100644 --- a/src/basic/socket-label.c +++ b/src/basic/socket-label.c @@ -142,6 +142,11 @@ int socket_address_listen( if (listen(fd, backlog) < 0) return -errno; + /* Let's trigger an inotify event on the socket node, so that anyone waiting for this socket to be connectable + * gets notified */ + if (p) + (void) touch(p); + r = fd; fd = -1; diff --git a/src/core/dbus.c b/src/core/dbus.c index b7d8af9..115d071 100644 --- a/src/core/dbus.c +++ b/src/core/dbus.c @@ -37,6 +37,7 @@ #include "dbus-unit.h" #include "dbus.h" #include "fd-util.h" +#include "fs-util.h" #include "log.h" #include "missing.h" #include "mkdir.h" @@ -1005,6 +1006,9 @@ static int bus_init_private(Manager *m) { if (r < 0) return log_error_errno(errno, "Failed to make private socket listening: %m"); + /* Generate an inotify event in case somebody waits for this socket to appear using inotify() */ + (void) touch(sa.un.sun_path); + r = sd_event_add_io(m->event, &s, fd, EPOLLIN, bus_on_connection, m); if (r < 0) return log_error_errno(r, "Failed to allocate event source: %m"); -- 2.7.4