Merge pull request #25483 from poettering/ppoll-usec-eintr

ppoll() + EINTR fixes

src/libsystemd/sd-bus/bus-socket.c

@@ -1308,8 +1308,11 @@ int bus_socket_process_opening(sd_bus *b) {
         assert(b->state == BUS_OPENING);
 
         events = fd_wait_for_event(b->output_fd, POLLOUT, 0);
-        if (events < 0)
+        if (events < 0) {
+                if (ERRNO_IS_TRANSIENT(events))
+                        return 0;
                 return events;
+        }
         if (!(events & (POLLOUT|POLLERR|POLLHUP)))
                 return 0;
 

src/libsystemd/sd-bus/sd-bus.c

@@ -2465,8 +2465,11 @@ _public_ int sd_bus_call(
                         left = UINT64_MAX;
 
                 r = bus_poll(bus, true, left);
-                if (r < 0)
+                if (r < 0) {
+                        if (ERRNO_IS_TRANSIENT(r))
+                                continue;
                         goto fail;
+                }
                 if (r == 0) {
                         r = -ETIMEDOUT;
                         goto fail;
@@ -3321,6 +3324,7 @@ static int bus_poll(sd_bus *bus, bool need_more, uint64_t timeout_usec) {
 }
 
 _public_ int sd_bus_wait(sd_bus *bus, uint64_t timeout_usec) {
+        int r;
 
         assert_return(bus, -EINVAL);
         assert_return(bus = bus_resolve(bus), -ENOPKG);
@@ -3335,7 +3339,11 @@ _public_ int sd_bus_wait(sd_bus *bus, uint64_t timeout_usec) {
         if (bus->rqueue_size > 0)
                 return 0;
 
-        return bus_poll(bus, false, timeout_usec);
+        r = bus_poll(bus, false, timeout_usec);
+        if (r < 0 && ERRNO_IS_TRANSIENT(r))
+                return 1; /* treat EINTR as success, but let's exit, so that the caller will call back into us soon. */
+
+        return r;
 }
 
 _public_ int sd_bus_flush(sd_bus *bus) {
@@ -3377,8 +3385,12 @@ _public_ int sd_bus_flush(sd_bus *bus) {
                         return 0;
 
                 r = bus_poll(bus, false, UINT64_MAX);
-                if (r < 0)
+                if (r < 0) {
+                        if (ERRNO_IS_TRANSIENT(r))
+                                continue;
+
                         return r;
+                }
         }
 }
 

src/libsystemd/sd-netlink/sd-netlink.c

@@ -464,13 +464,18 @@ static int netlink_poll(sd_netlink *nl, bool need_more, usec_t timeout_usec) {
 }
 
 int sd_netlink_wait(sd_netlink *nl, uint64_t timeout_usec) {
+        int r;
+
         assert_return(nl, -EINVAL);
         assert_return(!netlink_pid_changed(nl), -ECHILD);
 
         if (nl->rqueue_size > 0)
                 return 0;
 
-        return netlink_poll(nl, false, timeout_usec);
+        r = netlink_poll(nl, false, timeout_usec);
+        if (r < 0 && ERRNO_IS_TRANSIENT(r)) /* Convert EINTR to "something happened" and give user a chance to run some code before calling back into us */
+                return 1;
+        return r;
 }
 
 static int timeout_compare(const void *a, const void *b) {