io-util: make flush_fd() return how many bytes where flushed

This is useful so that callers know whether anything at all and how much
was flushed.

This patches through users of this functions to ensure that the return
values > 0 which may be returned now are not propagated in public APIs.

Also, users that ignore the return value are changed to do so explicitly
now.

diff --git a/src/basic/io-util.c b/src/basic/io-util.c
index 77c9bdc739d424076493ecfdc850fa2dc1f2e6f2..08ad42ed952468df310df00972cdecb3a051bfb5 100644 (file)
--- a/src/basic/io-util.c
+++ b/src/basic/io-util.c
@@ -33,6 +33,7 @@ int flush_fd(int fd) {
                 .fd = fd,
                 .events = POLLIN,
         };
+        int count = 0;
 
         /* Read from the specified file descriptor, until POLLIN is not set anymore, throwing away everything
          * read. Note that some file descriptors (notable IP sockets) will trigger POLLIN even when no data can be read
@@ -52,7 +53,7 @@ int flush_fd(int fd) {
                         return -errno;
 
                 } else if (r == 0)
-                        return 0;
+                        return count;
 
                 l = read(fd, buf, sizeof(buf));
                 if (l < 0) {
@@ -61,11 +62,13 @@ int flush_fd(int fd) {
                                 continue;
 
                         if (errno == EAGAIN)
-                                return 0;
+                                return count;
 
                         return -errno;
                 } else if (l == 0)
-                        return 0;
+                        return count;
+
+                count += (int) l;
         }
 }
 

diff --git a/src/core/manager.c b/src/core/manager.c
index 15720ada24f223b3b7de3cbb8f86974ec11e2361..860d58617fad787d54629491511de57a4489edb2 100644 (file)
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -263,7 +263,7 @@ static int manager_dispatch_ask_password_fd(sd_event_source *source,
 
         assert(m);
 
-        flush_fd(fd);
+        (void) flush_fd(fd);
 
         m->have_ask_password = have_ask_password();
         if (m->have_ask_password < 0)

diff --git a/src/libsystemd/sd-login/sd-login.c b/src/libsystemd/sd-login/sd-login.c
index e8adaa6823238f87baaf682010012ed05345ead9..69572d1a5156e8227700de18c5243195be5bae8b 100644 (file)
--- a/src/libsystemd/sd-login/sd-login.c
+++ b/src/libsystemd/sd-login/sd-login.c
@@ -1061,10 +1061,15 @@ _public_ sd_login_monitor* sd_login_monitor_unref(sd_login_monitor *m) {
 }
 
 _public_ int sd_login_monitor_flush(sd_login_monitor *m) {
+        int r;
 
         assert_return(m, -EINVAL);
 
-        return flush_fd(MONITOR_TO_FD(m));
+        r = flush_fd(MONITOR_TO_FD(m));
+        if (r < 0)
+                return r;
+
+        return 0;
 }
 
 _public_ int sd_login_monitor_get_fd(sd_login_monitor *m) {

diff --git a/src/libudev/libudev-queue.c b/src/libudev/libudev-queue.c
index b941afb77397449a612b1a1ee1abbdb0449a622d..85ceb263a3ad2fc8f5a3a621ec9a37fdb0ff766d 100644 (file)
--- a/src/libudev/libudev-queue.c
+++ b/src/libudev/libudev-queue.c
@@ -268,8 +268,16 @@ _public_ int udev_queue_get_fd(struct udev_queue *udev_queue) {
  * Returns: the result of clearing the watch for queue changes.
  */
 _public_ int udev_queue_flush(struct udev_queue *udev_queue) {
+        int r;
+
+        assert(udev_queue);
+
         if (udev_queue->fd < 0)
                 return -EINVAL;
 
-        return flush_fd(udev_queue->fd);
+        r = flush_fd(udev_queue->fd);
+        if (r < 0)
+                return r;
+
+        return 0;
 }

diff --git a/src/shared/ask-password-api.c b/src/shared/ask-password-api.c
index 346d8c9d24e82f1e4de0a1295dd7bf31fdb3cc40..99d6a9b143a2ea7a1d84aa8cca8e7d2bf5dcac5d 100644 (file)
--- a/src/shared/ask-password-api.c
+++ b/src/shared/ask-password-api.c
@@ -316,7 +316,7 @@ int ask_password_tty(
                 }
 
                 if (notify >= 0 && pollfd[POLL_INOTIFY].revents != 0)
-                        flush_fd(notify);
+                        (void) flush_fd(notify);
 
                 if (pollfd[POLL_TTY].revents == 0)
                         continue;

diff --git a/src/tty-ask-password-agent/tty-ask-password-agent.c b/src/tty-ask-password-agent/tty-ask-password-agent.c
index 6e9c10aeb037a6328711791dcf9ff89635dfc74a..d2648ead93147a9f48b056900f0f5bde5829a2de 100644 (file)
--- a/src/tty-ask-password-agent/tty-ask-password-agent.c
+++ b/src/tty-ask-password-agent/tty-ask-password-agent.c
@@ -159,7 +159,7 @@ static int ask_password_plymouth(
                 }
 
                 if (notify >= 0 && pollfd[POLL_INOTIFY].revents != 0)
-                        flush_fd(notify);
+                        (void) flush_fd(notify);
 
                 if (pollfd[POLL_SOCKET].revents == 0)
                         continue;