scrub/e2scrub.in

   1 #!/bin/bash
   2
   3 #  Copyright (C) 2018 Oracle.  All Rights Reserved.
   4 #
   5 #  Author: Darrick J. Wong <darrick.wong@oracle.com>
   6 #
   7 #  This program is free software; you can redistribute it and/or
   8 #  modify it under the terms of the GNU General Public License
   9 #  as published by the Free Software Foundation; either version 2
  10 #  of the License, or (at your option) any later version.
  11 #
  12 #  This program is distributed in the hope that it would be useful,
  13 #  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 #  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 #  GNU General Public License for more details.
  16 #
  17 #  You should have received a copy of the GNU General Public License
  18 #  along with this program; if not, write the Free Software Foundation,
  19 #  Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
  20
  21 # Automatically check an LVM-managed filesystem online.
  22 # We use lvm snapshots to do this, which means that we can only
  23 # check filesystems in VGs that have at least 256MB (or so) of
  24 # free space.
  25
  26 PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
  27
  28 if (( $EUID != 0 )); then
  29     echo "e2scrub must be run as root"
  30     exit 1
  31 fi
  32
  33 snap_size_mb=256
  34 fstrim=0
  35 reap=0
  36 e2fsck_opts=""
  37 conffile="@root_sysconfdir@/e2scrub.conf"
  38
  39 test -f "${conffile}" && . "${conffile}"
  40
  41 print_help() {
  42         echo "Usage: $0 [OPTIONS] mountpoint | device"
  43         echo
  44         echo "mountpoint must be on an LVM-managed block device"
  45         echo "-n: Show what commands e2scrub would execute."
  46         echo "-r: Remove e2scrub snapshot and exit, do not check anything."
  47         echo "-t: Run fstrim if successful."
  48         echo "-V: Print version information and exit."
  49 }
  50
  51 print_version() {
  52         echo "e2scrub @E2FSPROGS_VERSION@ (@E2FSPROGS_DATE@)"
  53 }
  54
  55 exitcode() {
  56         ret="$1"
  57
  58         # If we're being run as a service, the return code must fit the LSB
  59         # init script action error guidelines, which is to say that we
  60         # compress all errors to 1 ("generic or unspecified error", LSB 5.0
  61         # section 22.2) and hope the admin will scan the log for what
  62         # actually happened.
  63
  64         # We have to sleep 2 seconds here because journald uses the pid to
  65         # connect our log messages to the systemd service.  This is critical
  66         # for capturing all the log messages if the scrub fails, because the
  67         # fail service uses the service name to gather log messages for the
  68         # error report.
  69         if [ -n "${SERVICE_MODE}" ]; then
  70                 test "${ret}" -ne 0 && ret=1
  71                 sleep 2
  72         fi
  73
  74         exit "${ret}"
  75 }
  76
  77 while getopts "nrtV" opt; do
  78     case "${opt}" in
  79         "n") DBG="echo Would execute: " ;;
  80         "r") reap=1;;
  81         "t") fstrim=1;;
  82         "V") print_version; exitcode 0;;
  83         *) print_help; exitcode 2;;
  84         esac
  85 done
  86 shift "$((OPTIND - 1))"
  87
  88 arg="$1"
  89 if [ -z "${arg}" ]; then
  90         print_help
  91         exitcode 1
  92 fi
  93
  94 if ! type lsblk >& /dev/null ; then
  95     echo "e2scrub: can't find lsblk --- is util-linux installed?"
  96     exitcode 1
  97 fi
  98
  99 if ! type lvcreate >& /dev/null ; then
 100     echo "e2scrub: can't find lvcreate --- is lvm2 installed?"
 101     exitcode 1
 102 fi
 103
 104 # close file descriptor 3 (from cron) since it causes lvm to kvetch
 105 exec 3<&-
 106
 107 # Find the device for a given mountpoint
 108 dev_from_mount() {
 109         local mountpt="$(realpath "$1")"
 110
 111         lsblk -o NAME,FSTYPE,MOUNTPOINT -p -P -n 2> /dev/null | while read vars; do
 112                 eval "${vars}"
 113                 if [ "${mountpt}" != "${MOUNTPOINT}" ]; then
 114                         continue
 115                 fi
 116                 case "${FSTYPE}" in
 117                 ext[234])
 118                         echo "${NAME}"
 119                         return 0
 120                         ;;
 121                 esac
 122         done
 123         return 1
 124 }
 125
 126 # Check a device argument
 127 dev_from_arg() {
 128         local dev="$1"
 129         local fstype="$(lsblk -o FSTYPE -n "${dev}" 2> /dev/null)"
 130
 131         case "${fstype}" in
 132         ext[234])
 133                 echo "${dev}"
 134                 return 0
 135                 ;;
 136         esac
 137         return 1
 138 }
 139
 140 mnt_from_dev() {
 141         local dev="$1"
 142
 143         if [ -n "${dev}" ]; then
 144                 lsblk -o MOUNTPOINT -n "${dev}"
 145         fi
 146 }
 147
 148 # Construct block device path and mountpoint from argument
 149 if [ -b "${arg}" ]; then
 150         dev="$(dev_from_arg "${arg}")"
 151         mnt="$(mnt_from_dev "${dev}")"
 152 else
 153         dev="$(dev_from_mount "${arg}")"
 154         mnt="${arg}"
 155 fi
 156 if [ ! -e "${dev}" ]; then
 157         echo "${arg}: Not an ext[234] filesystem."
 158         print_help
 159         exitcode 16
 160 fi
 161
 162 # Make sure this is an LVM device we can snapshot
 163 lvm_vars="$(lvs --nameprefixes -o name,vgname,lv_role --noheadings "${dev}" 2> /dev/null)"
 164 eval "${lvm_vars}"
 165 if [ -z "${LVM2_VG_NAME}" ] || [ -z "${LVM2_LV_NAME}" ] ||
 166    echo "${LVM2_LV_ROLE}" | grep -q "snapshot"; then
 167         echo "${arg}: Not connnected to an LVM logical volume."
 168         print_help
 169         exitcode 16
 170 fi
 171 start_time="$(date +'%Y%m%d%H%M%S')"
 172 snap="${LVM2_LV_NAME}.e2scrub"
 173 snap_dev="/dev/${LVM2_VG_NAME}/${snap}"
 174
 175 teardown() {
 176         # Remove and wait for removal to succeed.
 177         ${DBG} lvremove -f "${LVM2_VG_NAME}/${snap}"
 178         while [ -e "${snap_dev}" ] && [ "$?" -eq "5" ]; do
 179                 sleep 0.5
 180                 ${DBG} lvremove -f "${LVM2_VG_NAME}/${snap}"
 181         done
 182 }
 183
 184 check() {
 185         # First we recover the journal, then we see if e2fsck tries any
 186         # non-optimization repairs.  If either of these two returns a
 187         # non-zero status (errors fixed or remaining) then this fs is bad.
 188         E2FSCK_FIXES_ONLY=1
 189         export E2FSCK_FIXES_ONLY
 190         ${DBG} "@root_sbindir@/e2fsck" -E journal_only -p ${e2fsck_opts} "${snap_dev}" || return $?
 191         ${DBG} "@root_sbindir@/e2fsck" -f -y ${e2fsck_opts} "${snap_dev}"
 192 }
 193
 194 mark_clean() {
 195         ${DBG} "@root_sbindir@/tune2fs" -C 0 -T "${start_time}" "${dev}"
 196 }
 197
 198 mark_corrupt() {
 199         ${DBG} "@root_sbindir@/tune2fs" -E force_fsck "${dev}"
 200 }
 201
 202 setup() {
 203         # Try to remove snapshot for 30s, bail out if we can't remove it.
 204         lvremove_deadline="$(( $(date "+%s") + 30))"
 205         ${DBG} lvremove -f "${LVM2_VG_NAME}/${snap}" 2>/dev/null
 206         while [ -e "${snap_dev}" ] && [ "$?" -eq "5" ] &&
 207               [ "$(date "+%s")" -lt "${lvremove_deadline}" ]; do
 208                 sleep 0.5
 209                 ${DBG} lvremove -f "${LVM2_VG_NAME}/${snap}"
 210         done
 211         if [ -e "${snap_dev}" ]; then
 212                 echo "${arg}: e2scrub snapshot is in use, cannot check!"
 213                 return 1
 214         fi
 215         # Create the snapshot, wait for device to appear.
 216         ${DBG} lvcreate -s -L "${snap_size_mb}m" -n "${snap}" "${LVM2_VG_NAME}/${LVM2_LV_NAME}"
 217         if [ $? -ne 0 ]; then
 218                 echo "${arg}: e2scrub snapshot FAILED, will not check!"
 219                 return 1
 220         fi
 221         ${DBG} udevadm settle 2> /dev/null
 222         return 0
 223 }
 224
 225 if [ "${reap}" -gt 0 ]; then
 226         if [ -e "${snap_dev}" ]; then
 227                 teardown 2> /dev/null
 228         fi
 229         exit 0
 230 fi
 231 if ! setup; then
 232         exitcode 8
 233 fi
 234 trap "teardown; exit 1" EXIT INT QUIT TERM
 235
 236 # Check and react
 237 check
 238 case "$?" in
 239 "0")
 240         # Clean check!
 241         echo "${arg}: Scrub succeeded."
 242         mark_clean
 243         teardown
 244         trap '' EXIT
 245
 246         # Trim the free space, which requires the snapshot be deleted.
 247         if [ "${fstrim}" -eq 1 ] && [ -d "${mnt}" ] && type fstrim > /dev/null 2>&1; then
 248                 echo "${arg}: Trimming free space."
 249                 fstrim -v "${mnt}"
 250         fi
 251
 252         ret=0
 253         ;;
 254 "8")
 255         # Operational error, what now?
 256         echo "${arg}: e2fsck operational error."
 257         teardown
 258         trap '' EXIT
 259         ret=8
 260         ;;
 261 *)
 262         # fsck failed.  Check if the snapshot is invalid; if so, make a
 263         # note of that at the end of the log.  This isn't necessarily a
 264         # failure because the mounted fs could have overflowed the
 265         # snapshot with regular disk writes /or/ our repair process
 266         # could have done it by repairing too much.
 267         #
 268         # If it's really corrupt we ought to fsck at next boot.
 269         is_invalid="$(lvs -o lv_snapshot_invalid --noheadings "${snap_dev}" | awk '{print $1}')"
 270         if [ -n "${is_invalid}" ]; then
 271                 echo "${arg}: Scrub FAILED due to invalid snapshot."
 272                 ret=8
 273         else
 274                 echo "${arg}: Scrub FAILED due to corruption!  Unmount and run e2fsck -y."
 275                 mark_corrupt
 276                 ret=6
 277         fi
 278         teardown
 279         trap '' EXIT
 280         ;;
 281 esac
 282
 283 exitcode "${ret}"