svn commit: r328813 - head/lib/libufs

[Kirk McKusick]

Author: mckusick
Date: Fri Feb  2 22:06:15 2018
New Revision: 328813
URL: https://svnweb.freebsd.org/changeset/base/328813

Log:
  In the sbwrite(3) function, ensure that the file descriptor has been
  upgraded to writable.
  
  Reported by: Kyle Evans <kevans at freebsd.org>

Modified:
  head/lib/libufs/sblock.c

Modified: head/lib/libufs/sblock.c
==============================================================================
--- head/lib/libufs/sblock.c	Fri Feb  2 22:05:36 2018	(r328812)
+++ head/lib/libufs/sblock.c	Fri Feb  2 22:06:15 2018	(r328813)
@@ -96,8 +96,15 @@ int
 sbwrite(struct uufsd *disk, int all)
 {
 	struct fs *fs;
+	int rv;
 
 	ERROR(disk, NULL);
+
+	rv = ufs_disk_write(disk);
+	if (rv == -1) {
+		ERROR(disk, "failed to open disk for writing");
+		return (-1);
+	}
 
 	fs = &disk->d_fs;
 	if ((errno = sbput(disk->d_fd, fs, all ? fs->fs_ncg : 0)) != 0) {