svn commit: r325860 - head/sbin/newfs

[Ed Maste]

Author: emaste
Date: Wed Nov 15 18:40:40 2017
New Revision: 325860
URL: https://svnweb.freebsd.org/changeset/base/325860

Log:
  newfs: warn if newer than kernel
  
  Creating a UFS filesystem with a newfs newer than the running kernel,
  and then mounting that filesystem, can lead to interesting failures.
  
  Add a safety belt to explicitly warn when newfs is newer than the
  running kernel.
  
  Reviewed by:	gjb, jhb, mckusick
  Sponsored by:	The FreeBSD Foundation
  Differential Revision:	https://reviews.freebsd.org/D12765

Modified:
  head/sbin/newfs/newfs.c

Modified: head/sbin/newfs/newfs.c
==============================================================================
--- head/sbin/newfs/newfs.c	Wed Nov 15 18:03:31 2017	(r325859)
+++ head/sbin/newfs/newfs.c	Wed Nov 15 18:40:40 2017	(r325860)
@@ -398,6 +398,10 @@ main(int argc, char *argv[])
 		if (pp != NULL)
 			pp->p_size *= secperblk;
 	}
+	if (getosreldate() < __FreeBSD_version) {
+		warnx("%s is newer than the running kernel and may not be compatible",
+		    getprogname());
+	}
 	mkfs(pp, special);
 	ufs_disk_close(&disk);
 	if (!jflag)