Index: head/lib/libufs/sblock.c
===================================================================
--- head/lib/libufs/sblock.c	(revision 328812)
+++ head/lib/libufs/sblock.c	(revision 328813)
@@ -1,202 +1,209 @@
 /*-
  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
  *
  * Copyright (c) 2002 Juli Mallett.  All rights reserved.
  *
  * This software was written by Juli Mallett <jmallett@FreeBSD.org> for the
  * FreeBSD project.  Redistribution and use in source and binary forms, with
  * or without modification, are permitted provided that the following
  * conditions are met:
  *
  * 1. Redistribution of source code must retain the above copyright notice,
  *    this list of conditions and the following disclaimer.
  * 2. Redistribution in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/mount.h>
 #include <sys/disklabel.h>
 #include <sys/stat.h>
 
 #include <ufs/ufs/ufsmount.h>
 #include <ufs/ufs/dinode.h>
 #include <ufs/ffs/fs.h>
 
 #include <errno.h>
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
 #include <unistd.h>
 
 #include <libufs.h>
 
 int
 sbread(struct uufsd *disk)
 {
 	struct fs *fs;
 
 	ERROR(disk, NULL);
 
 	if ((errno = sbget(disk->d_fd, &fs, -1)) != 0) {
 		switch (errno) {
 		case EIO:
 			ERROR(disk, "non-existent or truncated superblock");
 			break;
 		case ENOENT:
 			ERROR(disk, "no usable known superblock found");
 			break;
 		case ENOSPC:
 			ERROR(disk, "failed to allocate space for superblock "
 			    "information");
 			break;
 		case EINVAL:
 			ERROR(disk, "The previous newfs operation on this "
 			    "volume did not complete.\nYou must complete "
 			    "newfs before using this volume.");
 			break;
 		default:
 			ERROR(disk, "unknown superblock read error");
 			errno = EIO;
 			break;
 		}
 		disk->d_ufs = 0;
 		return (-1);
 	}
 	memcpy(&disk->d_fs, fs, fs->fs_sbsize);
 	free(fs);
 	fs = &disk->d_fs;
 	if (fs->fs_magic == FS_UFS1_MAGIC)
 		disk->d_ufs = 1;
 	if (fs->fs_magic == FS_UFS2_MAGIC)
 		disk->d_ufs = 2;
 	disk->d_bsize = fs->fs_fsize / fsbtodb(fs, 1);
 	disk->d_sblock = fs->fs_sblockloc / disk->d_bsize;
 	disk->d_sbcsum = fs->fs_csp;
 	return (0);
 }
 
 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) {
 		switch (errno) {
 		case EIO:
 			ERROR(disk, "failed to write superblock");
 			break;
 		default:
 			ERROR(disk, "unknown superblock write error");
 			errno = EIO;
 			break;
 		}
 		return (-1);
 	}
 	return (0);
 }
 
 /*
  * These are the low-level functions that actually read and write
  * the superblock and its associated data. The actual work is done by
  * the functions ffs_sbget and ffs_sbput in /sys/ufs/ffs/ffs_subr.c.
  */
 static int use_pread(void *devfd, off_t loc, void **bufp, int size);
 static int use_pwrite(void *devfd, off_t loc, void *buf, int size);
 
 /*
  * Read a superblock from the devfd device allocating memory returned
  * in fsp. Also read the superblock summary information.
  */
 int
 sbget(int devfd, struct fs **fsp, off_t sblockloc)
 {
 
 	return (ffs_sbget(&devfd, fsp, sblockloc, "user", use_pread));
 }
 
 /*
  * A read function for use by user-level programs using libufs.
  */
 static int
 use_pread(void *devfd, off_t loc, void **bufp, int size)
 {
 	int fd;
 
 	fd = *(int *)devfd;
 	if ((*bufp = malloc(size)) == NULL)
 		return (ENOSPC);
 	if (pread(fd, *bufp, size, loc) != size)
 		return (EIO);
 	return (0);
 }
 
 /*
  * Write a superblock to the devfd device from the memory pointed to by fs.
  * Also write out the superblock summary information but do not free the
  * summary information memory.
  *
  * Additionally write out numaltwrite of the alternate superblocks. Use
  * fs->fs_ncg to write out all of the alternate superblocks.
  */
 int
 sbput(int devfd, struct fs *fs, int numaltwrite)
 {
 	struct csum *savedcsp;
 	off_t savedactualloc;
 	int i, error;
 
 	if ((error = ffs_sbput(&devfd, fs, fs->fs_sblockactualloc,
 	     use_pwrite)) != 0)
 		return (error);
 	if (numaltwrite == 0)
 		return (0);
 	savedactualloc = fs->fs_sblockactualloc;
 	savedcsp = fs->fs_csp;
 	fs->fs_csp = NULL;
 	for (i = 0; i < numaltwrite; i++) {
 		fs->fs_sblockactualloc = dbtob(fsbtodb(fs, cgsblock(fs, i)));
 		if ((error = ffs_sbput(&devfd, fs, fs->fs_sblockactualloc,
 		     use_pwrite)) != 0) {
 			fs->fs_sblockactualloc = savedactualloc;
 			fs->fs_csp = savedcsp;
 			return (-1);
 		}
 	}
 	fs->fs_sblockactualloc = savedactualloc;
 	fs->fs_csp = savedcsp;
 	return (0);
 }
 
 /*
  * A write function for use by user-level programs using sbput in libufs.
  */
 static int
 use_pwrite(void *devfd, off_t loc, void *buf, int size)
 {
 	int fd;
 
 	fd = *(int *)devfd;
 	if (pwrite(fd, buf, size, loc) != size)
 		return (EIO);
 	return (0);
 }