Index: lib/libutil/flopen.3
===================================================================
--- lib/libutil/flopen.3
+++ lib/libutil/flopen.3
@@ -25,7 +25,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd July 28, 2017
+.Dd March 19, 2021
 .Dt FLOPEN 3
 .Os
 .Sh NAME
@@ -49,21 +49,12 @@
 The
 .Fn flopen
 function opens or creates a file and acquires an exclusive lock on it.
-It is essentially equivalent with calling
+It is equivalent to
 .Fn open
-with the same parameters followed by
-.Fn flock
-with an
-.Fa operation
+with the
+.Fa flags
 argument of
-.Dv LOCK_EX ,
-except that
-.Fn flopen
-will attempt to detect and handle races that may occur between opening
-/ creating the file and locking it.
-Thus, it is well suited for opening lock files, PID files, spool
-files, mailboxes and other kinds of files which are used for
-synchronization between processes.
+.Dv O_EXLOCK .
 .Pp
 If
 .Fa flags
Index: lib/libutil/flopen.c
===================================================================
--- lib/libutil/flopen.c
+++ lib/libutil/flopen.c
@@ -39,87 +39,19 @@
 
 #include <libutil.h>
 
-/*
- * Reliably open and lock a file.
- *
- * Please do not modify this code without first reading the revision history
- * and discussing your changes with <des@freebsd.org>.  Don't be fooled by the
- * code's apparent simplicity; there would be no need for this function if it
- * was easy to get right.
- */
 static int
 vflopenat(int dirfd, const char *path, int flags, va_list ap)
 {
-	int fd, operation, serrno, trunc;
-	struct stat sb, fsb;
 	mode_t mode;
 
-#ifdef O_EXLOCK
-	flags &= ~O_EXLOCK;
-#endif
-
 	mode = 0;
 	if (flags & O_CREAT) {
 		mode = (mode_t)va_arg(ap, int); /* mode_t promoted to int */
 	}
 
-        operation = LOCK_EX;
-        if (flags & O_NONBLOCK)
-                operation |= LOCK_NB;
-
-	trunc = (flags & O_TRUNC);
-	flags &= ~O_TRUNC;
-
-	for (;;) {
-		if ((fd = openat(dirfd, path, flags, mode)) == -1)
-			/* non-existent or no access */
-			return (-1);
-		if (flock(fd, operation) == -1) {
-			/* unsupported or interrupted */
-			serrno = errno;
-			(void)close(fd);
-			errno = serrno;
-			return (-1);
-		}
-		if (fstatat(dirfd, path, &sb, 0) == -1) {
-			/* disappeared from under our feet */
-			(void)close(fd);
-			continue;
-		}
-		if (fstat(fd, &fsb) == -1) {
-			/* can't happen [tm] */
-			serrno = errno;
-			(void)close(fd);
-			errno = serrno;
-			return (-1);
-		}
-		if (sb.st_dev != fsb.st_dev ||
-		    sb.st_ino != fsb.st_ino) {
-			/* changed under our feet */
-			(void)close(fd);
-			continue;
-		}
-		if (trunc && ftruncate(fd, 0) != 0) {
-			/* can't happen [tm] */
-			serrno = errno;
-			(void)close(fd);
-			errno = serrno;
-			return (-1);
-		}
-		/*
-		 * The following change is provided as a specific example to
-		 * avoid.
-		 */
-#if 0
-		if (fcntl(fd, F_SETFD, FD_CLOEXEC) != 0) {
-			serrno = errno;
-			(void)close(fd);
-			errno = serrno;
-			return (-1);
-		}
-#endif
-		return (fd);
-	}
+	flags &= ~O_SHLOCK;
+	flags |= O_EXLOCK;
+	return (openat(dirfd, path, flags, mode));
 }
 
 int