Change exit() to _exit() in the child process. exit flushes stdio file buffers,

_exit doesn't. If there were some open files, an error in exec and subsequent
exit() would cause the buffers to be flushed twice.

Example:

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/wait.h>

int main()
{
	printf("buu");
	if (!fork()) {
		execl("/bin/true-not-exists", "/bin/true", NULL);
		exit(1);
	}
	wait(NULL);
	return 0;
}

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com

---
 daemons/dmeventd/libdevmapper-event.c |    2 +-
 lib/misc/lvm-exec.c                   |    2 +-
 test/harness.c                        |    3 ++-
 tools/dmsetup.c                       |    2 +-
 4 files changed, 5 insertions(+), 4 deletions(-)

daemons/dmeventd/libdevmapper-event.c

@@ -438,7 +438,7 @@ static int _start_daemon(struct dm_event_fifos *fifos)
 
 	else if (!pid) {
 		execvp(DMEVENTD_PATH, NULL);
-		exit(EXIT_FAILURE);
+		_exit(EXIT_FAILURE);
 	} else {
 		if (waitpid(pid, &status, 0) < 0)
 			log_error("Unable to start dmeventd: %s",

lib/misc/lvm-exec.c

@@ -68,7 +68,7 @@ int exec_cmd(struct cmd_context *cmd, const char *const argv[])
 		/* FIXME Use execve directly */
 		execvp(argv[0], (char **const) argv);
 		log_sys_error("execvp", argv[0]);
-		exit(errno);
+		_exit(errno);
 	}
 
 	/* Parent */

test/harness.c

@@ -90,7 +90,8 @@ void run(int i, char *f) {
 		dup2(fds[0], 2);
 		execlp("bash", "bash", f, NULL);
 		perror("execlp");
-		exit(202);
+		fflush(stderr);
+		_exit(202);
 	} else {
 		char buf[128];
 		snprintf(buf, 128, "%s ...", f);

tools/dmsetup.c

@@ -1055,7 +1055,7 @@ static int _exec_command(const char *name)
 
 	if (!(pid = fork())) {
 		execvp(args[0], args);
-		exit(127);
+		_exit(127);
 	} else if (pid < (pid_t) 0)
 		return 0;