freebsd-skq/sbin
mckusick 2c9178edde Normally when an attempt is made to mount a UFS/FFS filesystem whose
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
2018-12-06 00:09:39 +00:00
..
adjkerntz various: general adoption of SPDX licensing ID tags. 2017-11-27 15:37:16 +00:00
bectl bectl: sync usage with man page, removing stray multibyte characters 2018-11-26 15:11:32 +00:00
bsdlabel Move disktab to sbin/bsdlabel/ 2018-09-18 20:52:24 +00:00
camcontrol NVME support is only for x86 and powerpc64. 2018-06-14 01:15:19 +00:00
ccdconfig ccdconfig: Move VCS tags to be more consistent with our style. 2017-12-30 00:26:42 +00:00
clri In preparation for adding inode check-hashes, clean up and 2018-11-13 21:40:56 +00:00
comcontrol various: general adoption of SPDX licensing ID tags. 2017-11-27 15:37:16 +00:00
conscontrol various: general adoption of SPDX licensing ID tags. 2017-11-27 15:37:16 +00:00
ddb Move ddb.conf to sbin/ddb/ and switch to CONFS. 2018-08-11 13:25:39 +00:00
decryptcore Make decryptcore(8) buildable. 2018-09-19 07:07:03 +00:00
devd Further research shows usbdump(8) is what we should point people at 2018-11-02 22:18:02 +00:00
devfs Move all devfs related files to sbin/devfs/ 2018-08-22 15:55:23 +00:00
devmatch Add in a missing newline 2018-08-25 15:47:52 +00:00
dhclient capsicum: use a new capsicum helpers in tools 2018-11-04 19:24:49 +00:00
dmesg General further adoption of SPDX licensing ID tags. 2017-11-20 19:49:47 +00:00
dump Normally when an attempt is made to mount a UFS/FFS filesystem whose 2018-12-06 00:09:39 +00:00
dumpfs The goal of this change is to prevent accidental foot shooting by 2018-02-08 23:06:58 +00:00
dumpon Avoid clobbering a user-specified -g value after r340547. 2018-11-20 18:10:56 +00:00
etherswitchcfg Finish removing FDDI and tokenring media support. 2018-04-23 21:10:33 +00:00
fdisk Allow fdisk(8) to deal with sectors larger than 2048 2018-10-25 12:13:13 +00:00
ffsinfo In preparation for adding inode check-hashes, clean up and 2018-11-13 21:40:56 +00:00
fsck various: general adoption of SPDX licensing ID tags. 2017-11-27 15:37:16 +00:00
fsck_ffs Normally when an attempt is made to mount a UFS/FFS filesystem whose 2018-12-06 00:09:39 +00:00
fsck_msdosfs Detect and handle invalid number of FATs 2018-07-13 02:02:16 +00:00
fsdb In preparation for adding inode check-hashes, change the fsck_ffs 2018-10-31 05:17:53 +00:00
fsirand Normally when an attempt is made to mount a UFS/FFS filesystem whose 2018-12-06 00:09:39 +00:00
gbde various: general adoption of SPDX licensing ID tags. 2017-11-27 15:37:16 +00:00
geom Add the "-t" option to geom(8) utility, to display geoms hierarchy. 2018-09-14 15:29:45 +00:00
ggate ggated: do not expose stack data in sendfail() 2018-12-04 15:25:15 +00:00
growfs Normally when an attempt is made to mount a UFS/FFS filesystem whose 2018-12-06 00:09:39 +00:00
gvinum gvinum: revert WARNS change in Makefile 2018-06-17 01:39:22 +00:00
hastctl various: general adoption of SPDX licensing ID tags. 2017-11-27 15:37:16 +00:00
hastd Revert 335888 ("Ensure va_list is declared by including stdarg.h.") 2018-07-03 15:48:34 +00:00
ifconfig Initial implementation of draft-ietf-6man-ipv6only-flag. 2018-10-30 20:08:48 +00:00
init Move the rc framework out of sbin/init into libexec/rc. 2018-10-17 16:49:11 +00:00
ipf rescue ipf: Remove hacks and link in libipf directly. 2017-11-10 07:52:58 +00:00
ipfw Add ability to request listing and deleting only for dynamic states. 2018-12-04 16:12:43 +00:00
iscontrol various: general adoption of SPDX licensing ID tags. 2017-11-27 15:37:16 +00:00
kldconfig various: general adoption of SPDX licensing ID tags. 2017-11-27 15:37:16 +00:00
kldload various: general adoption of SPDX licensing ID tags. 2017-11-27 15:37:16 +00:00
kldstat Allow three digits of module id without breaking table alignment. 2018-07-02 09:14:00 +00:00
kldunload various: general adoption of SPDX licensing ID tags. 2017-11-27 15:37:16 +00:00
ldconfig Make ldconfig(8) atomic, by removing an unneccessary call to unlink(2) 2018-08-09 11:46:12 +00:00
md5 capsicum: use a new capsicum helpers in tools 2018-11-04 19:24:49 +00:00
mdconfig various: general adoption of SPDX licensing ID tags. 2017-11-27 15:37:16 +00:00
mdmfs mdmfs(8): Check for other types of helper-program failure 2018-10-20 21:33:00 +00:00
mknod General further adoption of SPDX licensing ID tags. 2017-11-20 19:49:47 +00:00
mksnap_ffs various: general adoption of SPDX licensing ID tags. 2017-11-27 15:37:16 +00:00
mount When getting mount information for all filesystems, mount uses the 2018-08-07 21:17:45 +00:00
mount_cd9660 Advise reader to also see mdconfig(8) in mount_cd9660(8). 2018-08-11 08:34:24 +00:00
mount_fusefs mount_fusefs.8: expand HISTORY section 2018-11-17 21:35:01 +00:00
mount_msdosfs mount_msdosfs: do not fail mounts requiring locale name conversion table 2018-10-27 16:41:34 +00:00
mount_nfs General further adoption of SPDX licensing ID tags. 2017-11-20 19:49:47 +00:00
mount_nullfs General further adoption of SPDX licensing ID tags. 2017-11-20 19:49:47 +00:00
mount_udf General further adoption of SPDX licensing ID tags. 2017-11-20 19:49:47 +00:00
mount_unionfs General further adoption of SPDX licensing ID tags. 2017-11-20 19:49:47 +00:00
nandfs various: general adoption of SPDX licensing ID tags. 2017-11-27 15:37:16 +00:00
natd DIRDEPS_BUILD: Update dependencies. 2017-10-31 00:07:04 +00:00
newfs In preparation for adding inode check-hashes, clean up and 2018-11-13 21:40:56 +00:00
newfs_msdos Added option to cluster-align the start of the root directory. 2018-06-15 06:03:40 +00:00
newfs_nandfs various: general adoption of SPDX licensing ID tags. 2017-11-27 15:37:16 +00:00
nfsiod General further adoption of SPDX licensing ID tags. 2017-11-20 19:49:47 +00:00
nos-tun various: general adoption of SPDX licensing ID tags. 2017-11-27 15:37:16 +00:00
nvmecontrol Fix typo in comment 2018-12-02 23:13:45 +00:00
pfctl pfctl: Populate ifname in ifa_lookup() 2018-11-08 21:53:09 +00:00
pflogd DIRDEPS_BUILD: Update dependencies. 2017-10-31 00:07:04 +00:00
ping libcasper: ange the name of limits in cap_dns so the intentions are obvious. 2018-11-12 15:52:45 +00:00
ping6 General further adoption of SPDX licensing ID tags. 2017-11-20 19:49:47 +00:00
quotacheck Normally when an attempt is made to mount a UFS/FFS filesystem whose 2018-12-06 00:09:39 +00:00
rcorder rcorder(8): add support for /etc/rc.resume, so it calls "rcorder -k resume" 2018-10-27 17:21:13 +00:00
reboot Fix "fasthalt" to halt instead of reboot 2018-09-14 18:12:30 +00:00
recoverdisk SPDX: use the Beerware identifier. 2017-11-30 20:33:45 +00:00
resolvconf sbin: normalize paths using SRCTOP-relative paths or :H when possible 2017-03-04 11:33:01 +00:00
restore Re-enable reading byte swapped NFS_MAGIC dumps. 2018-08-11 16:12:23 +00:00
route route(8): correctly return exit status when "-q" flag is used. 2018-10-27 07:59:19 +00:00
routed When bind fails, make sure we closed the socket we tried to bind the 2017-12-28 05:34:24 +00:00
rtsol DIRDEPS_BUILD: Update dependencies. 2017-10-31 00:07:04 +00:00
savecore Restore /var/crash permissions to 0750, as declared in mtree file. After 2018-12-04 12:34:22 +00:00
sconfig DIRDEPS_BUILD: Update dependencies. 2017-10-31 00:07:04 +00:00
setkey General further adoption of SPDX licensing ID tags. 2017-11-20 19:49:47 +00:00
shutdown shutdown: Fix r327476 by adding init 2018-01-02 09:02:42 +00:00
spppcontrol various: general adoption of SPDX licensing ID tags. 2017-11-27 15:37:16 +00:00
sunlabel General further adoption of SPDX licensing ID tags. 2017-11-20 19:49:47 +00:00
swapon General further adoption of SPDX licensing ID tags. 2017-11-20 19:49:47 +00:00
sysctl sysctl(8): Add a standard exit status section. 2018-09-24 20:46:45 +00:00
tests Merge ^/user/ngie/release-pkg-fix-tests to unbreak how test files are installed 2016-05-04 23:20:53 +00:00
tunefs In preparation for adding inode check-hashes, clean up and 2018-11-13 21:40:56 +00:00
umount umount: remove sync(2) call when used with -f 2018-09-13 13:57:42 +00:00
zfsbootcfg DIRDEPS_BUILD: Update dependencies. 2017-10-31 00:07:04 +00:00
Makefile Rename be(1) to bectl(8); continues to live in /sbin 2018-07-24 13:21:44 +00:00
Makefile.amd64 NVME support is only for x86 and powerpc64. 2018-06-14 01:15:19 +00:00
Makefile.arm
Makefile.i386 NVME support is only for x86 and powerpc64. 2018-06-14 01:15:19 +00:00
Makefile.inc
Makefile.mips
Makefile.powerpc64 NVME support is only for x86 and powerpc64. 2018-06-14 01:15:19 +00:00
Makefile.sparc64