treewide: sanitize loop_write

loop_write() didn't follow the usual systemd rules and returned status
partially in errno and required extensive checks from callers. Some of
the callers dealt with this properly, but many did not, treating
partial writes as successful. Simplify things by conforming to usual rules.

1 files changed, 3 insertions, 6 deletions

diff --git a/src/systemctl/systemctl.c b/src/systemctl/systemctl.c
index d356686f7..6e48671ee 100644
--- a/src/systemctl/systemctl.c
+++ b/src/systemctl/systemctl.c
@@ -7246,12 +7246,9 @@ static int talk_initctl(void) {
                 return -errno;
         }
 
-        errno = 0;
-        r = loop_write(fd, &request, sizeof(request), false) != sizeof(request);
-        if (r) {
-                log_error_errno(errno, "Failed to write to "INIT_FIFO": %m");
-                return errno > 0 ? -errno : -EIO;
-        }
+        r = loop_write(fd, &request, sizeof(request), false);
+        if (r < 0)
+                return log_error_errno(r, "Failed to write to "INIT_FIFO": %m");
 
         return 1;
 }