pidfile: stop making pidfile error a special case

In case of -daemonize, we write non-zero to the daemon
pipe only if pidfile creation failed, so the parent will
report error about pidfile problem.  There's no need to
make special case for this, since all other errors are
reported by the child just fine.  Let the parent report
error and simplify logic in os_daemonize().

This way, we don't need os_pidfile_error() function, since
it only prints error now, so put the error reporting printf
into the only place where qemu_create_pidfile() is called,
in vl.c.

While at it, fix wrong indentation in os_daemonize().

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

1 files changed, 8 insertions, 23 deletions

diff --git a/os-posix.c b/os-posix.c
index eada8d4685..52e989797d 100644
--- a/os-posix.c
+++ b/os-posix.c
@@ -221,18 +221,14 @@ void os_daemonize(void)
             do {
                 len = read(fds[0], &status, 1);
             } while (len < 0 && errno == EINTR);
-            if (len != 1) {
-                exit(1);
-            }
-            else if (status == 1) {
-                fprintf(stderr, "Could not acquire pidfile\n");
-                exit(1);
-            } else {
-                exit(0);
-            }
-            } else if (pid < 0) {
-                exit(1);
-            }
+
+            /* only exit successfully if our child actually wrote
+             * a one-byte zero to our pipe, upon successful init */
+            exit(len == 1 && status == 0 ? 0 : 1);
+
+        } else if (pid < 0) {
+            exit(1);
+        }
 
         close(fds[0]);
         daemon_pipe = fds[1];
@@ -290,17 +286,6 @@ void os_setup_post(void)
     }
 }
 
-void os_pidfile_error(void)
-{
-    if (daemonize) {
-        uint8_t status = 1;
-        if (write(daemon_pipe, &status, 1) != 1) {
-            perror("daemonize. Writing to pipe\n");
-        }
-    } else
-        fprintf(stderr, "Could not acquire pid file: %s\n", strerror(errno));
-}
-
 void os_set_line_buffering(void)
 {
     setvbuf(stdout, NULL, _IOLBF, 0);