mirror of
https://github.com/freebsd/freebsd-src
synced 2024-09-06 17:18:32 +00:00
![Kirk McKusick](/assets/img/avatar_default.png)
superblock has a check-hash error, an error message noting the superblock check-hash failure is printed and the mount fails. The administrator then runs fsck to repair the filesystem and when successful, the filesystem can once again be mounted. This approach fails if the filesystem in question is a root filesystem from which you are trying to boot. Here, the loader fails when trying to access the filesystem to get the kernel to boot. So it is necessary to allow the loader to ignore the superblock check-hash error and make a best effort to read the kernel. The filesystem may be suffiently corrupted that the read attempt fails, but there is no harm in trying since the loader makes no attempt to write to the filesystem. Once the kernel is loaded and starts to run, it attempts to mount its root filesystem. Once again, failure means that it breaks to its prompt to ask where to get its root filesystem. Unless you have an alternate root filesystem, you are stuck. Since the root filesystem is initially mounted read-only, it is safe to make an attempt to mount the root filesystem with the failed superblock check-hash. Thus, when asked to mount a root filesystem with a failed superblock check-hash, the kernel prints a warning message that the root filesystem superblock check-hash needs repair, but notes that it is ignoring the error and proceeding. It does mark the filesystem as needing an fsck which prevents it from being enabled for writing until fsck has been run on it. The net effect is that the reboot fails to single user, but at least at that point the administrator has the tools at hand to fix the problem. Reported by: Rick Macklem (rmacklem@) Discussed with: Warner Losh (imp@) Sponsored by: Netflix
210 lines
5.4 KiB
C
210 lines
5.4 KiB
C
/*-
|
|
* 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, STDSB)) != 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);
|
|
}
|