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Direktori : /lib/open-iscsi/ |
Current File : //lib/open-iscsi/umountiscsi.sh |
#!/bin/sh # # This script umounts mounted iSCSI devices on shutdown, if possible. # It is supposed to catch most use cases but is not designed to work # for every corner-case. It handles LVM and multipath, but only if # one of the following stackings is used: # LVM -> multipath -> iSCSI # multipath -> iSCSI # LVM -> iSCSI # LVM -> LUKS -> multipath -> iSCSI # LVM -> LUKS -> iSCSI # LUKS -> LVM -> multipath -> iSCSI # LUKS -> multipath -> iSCSI # LUKS -> LVM -> iSCSI # LUKS -> iSCSI # It does not try to umount anything belonging to any device that is # also used as a backing store for the root filesystem. Any iSCSI # device part of the backing store of the root filesystem will be noted # in /run/open-iscsi/shutdown-keep-sessions, so that the session not be # closed on shutdown. # # KNOWN ISSUES: # - It doesn't handle submounts properly in all corner cases. # Specifically, it doesn't handle a non-iSCSI mount below an # iSCSI mount if it isn't also marked _netdev in /etc/fstab. # - It does not handle other things device mapper can do, such as # RAID, crypto, manual mappings of parts of disks, etc. # - It doesn't try to kill programs still accessing those mounts, # umount will just fail then. # - It doesn't handle more complicated stackings such as overlayfs, # FUSE filesystems, loop devices, etc. # - It doesn't handle swap. # # LONG TERM GOAL: # - In the long term, there should be a solution where for each part # of the stacking (device mapper, LVM, overlayfs, etc.) explicit # depdendencies are declared with the init system such that it can # be automatically dismantled. That would make this script # superfluous and also not be a layering violation, as it # currently is. # # CODING CHOICES: # - On systems running sysvinit, this script might be called without # /usr being mounted, so a lot of very useful commands are not # available: head, tail, stat, awk, etc. This makes the script # quite ugly at places, but that can't be avoided. # # Author: Christian Seiler <christian@iwakd.de> # # Make sure we don't include /usr in our path, else future modifications # to this script might accidentally use something from there and cause # failure on separate-/usr sysvinit systems that isn't immediately # noticed. PATH=/sbin:/bin EXCLUDE_MOUNTS_AT_SHUTDOWN="" if [ -f /etc/default/open-iscsi ]; then . /etc/default/open-iscsi fi MULTIPATH=/sbin/multipath PVS=/sbin/pvs LVS=/sbin/lvs VGS=/sbin/vgs VGCHANGE=/sbin/vgchange CRYPTSETUP=/sbin/cryptsetup DMSETUP=/sbin/dmsetup if [ -x $PVS ] && [ -x $LVS ] && [ -x $VGCHANGE ] ; then HAVE_LVM=1 else HAVE_LVM=0 fi if [ -x $CRYPTSETUP ] && [ -x $DMSETUP ] ; then HAVE_LUKS=1 else HAVE_LUKS=0 fi DRY_RUN=0 # We need to make sure that we don't try to umount the root device # and for systemd systems, also /usr (which is pre-mounted in initrd # there). EXCLUDE_MOUNTS="/" if [ -d /run/systemd/system ] ; then EXCLUDE_MOUNTS="$EXCLUDE_MOUNTS /usr" fi EXCLUDE_MOUNTS="${EXCLUDE_MOUNTS}${EXCLUDE_MOUNTS_AT_SHUTDOWN+ $EXCLUDE_MOUNTS_AT_SHUTDOWN}" unset _EXCLUDE_MOUNTS error_usage() { echo "Usage: $0 [--dry-run | --timeout secs]" >&2 exit 1 } timeout=0 if [ $# -gt 2 ] ; then error_usage fi if [ $# -eq 2 ] ; then if [ x"$1"x != x"--timeout"x ] ; then error_usage fi case "$2" in (-1) timeout="$2" ;; (*[!0-9]*|"") error_usage ;; (*) timeout="$2" ;; esac elif [ $# -eq 1 ] ; then if [ x"$1"x != x"--dry-run"x ] ; then error_usage fi DRY_RUN=1 fi # poor man's hash implementation using shell variables hash_keys() { _hash_keys_hash_key_prefix="${1}_" ( IFS='=' set | while read var value ; do if [ x"${var#$_hash_keys_hash_key_prefix}"x != x"${var}"x ] ; then printf '%s\n' "${var#$_hash_keys_hash_key_prefix}" fi done ) } hash_clear() { for k in $(hash_keys "$1") ; do unset "${1}_${k}" done } hash_get() { _hash_get_var="$2_$(printf '%s' "$3" | sed 's%[^A-Za-z0-9_]%_%g')" eval _hash_get_value=\$${_hash_get_var} eval $1=\${_hash_get_value} } hash_set() { _hash_set_var="$1_$(printf '%s' "$2" | sed 's%[^A-Za-z0-9_]%_%g')" eval ${_hash_set_var}=\${3} } hash_unset() { _hash_set_var="$1_$(printf '%s' "$2" | sed 's%[^A-Za-z0-9_]%_%g')" unset ${_hash_set_var} } in_set() { eval _set=\$$1 case "${_set}" in ("$2"|*" $2"|"$2 "*|*" $2 "*) return 0 ;; (*) return 1 ;; esac } _add_to_set() { eval _set=\$$1 case "${_set}" in ("$2"|*" $2"|"$2 "*|*" $2 "*) ;; ("") _set="$2" ;; (*) _set="${_set} $2" ;; esac eval $1=\${_set} } add_to_set() { _add_to_set_set="$1" shift for _add_to_set_val in "$@" ; do _add_to_set "${_add_to_set_set}" "${_add_to_set_val}" done } hash_add_to_set() { _hash_add_to_set_var="$1_$(printf '%s' "$2" | sed 's%[^A-Za-z0-9_]%_%g')" shift shift add_to_set "${_hash_add_to_set_var}" "$@" } device_majmin() { eval $1=\"\" _majmin_dec=$(LC_ALL=C ls -lnd /dev/"$2" | while read _perms _links _uid _gid _majcomma _min _rest ; do if [ x"${_majcomma%,}"x != x"${_majcomma}"x ] ; then printf '%s' ${_majcomma%,}:${_min} fi break done) [ -n "${_majmin_dec}" ] || return eval $1=\${_majmin_dec} } get_lvm_vgs() { # handle the case where we didn't get passed any PVs # at all [ $# -gt 0 ] || return 0 # subshell for pwd change ( cd /dev $PVS --noheadings -o vg_name "$@" 2>/dev/null ) } enumerate_luks() { hash_clear LUKS_DEVICES_REVERSE_MAP _all_crypt_devices=$($DMSETUP info --noheadings -o name -c -S subsystem=CRYPT 2>/dev/null || :) for _crypt_device in ${_all_crypt_devices} ; do [ -b "/dev/mapper/${_crypt_device}" ] || continue _crypt_device="$(readlink -fe "/dev/mapper/${_crypt_device}" 2>/dev/null || :)" _crypt_device="${_crypt_device#/dev/}" [ -b "/dev/${_crypt_device}" ] || continue # dmsetup deps is weird, it outputs the following: # 1 dependencies : (XYZ) _dep=$($DMSETUP deps -o blkdevname "/dev/${_crypt_device}" | sed -n '1s%.*: (\(.*\)).*%\1%p') if [ -n "$_dep" ] && [ -b "/dev/${_dep}" ] ; then _dep="$(readlink -fe "/dev/$_dep" 2>/dev/null || :)" _dep="${_dep#/dev/}" fi if [ -n "$_dep" ] && [ -b "/dev/${_dep}" ] ; then hash_set LUKS_DEVICES_REVERSE_MAP "${_dep}" "${_crypt_device}" fi done } enumerate_iscsi_devices() { # Empty arrays iscsi_disks="" iscsi_partitions="" iscsi_multipath_disks="" iscsi_multipath_disk_aliases="" iscsi_multipath_partitions="" iscsi_lvm_vgs="" iscsi_lvm_lvs="" iscsi_potential_mount_sources="" iscsi_luks_pass1="" iscsi_luks_pass2="" hash_clear ISCSI_DEVICE_SESSIONS hash_clear ISCSI_MPALIAS_SESSIONS hash_clear ISCSI_LVMVG_SESSIONS hash_clear ISCSI_NUMDEVICE_SESSIONS ISCSI_EXCLUDED_SESSIONS="" # We first need to generate a global reverse mapping of all # cryptsetup (e.g. LUKS) devices, because there's no easy way # to query "is this the encrypted backing of an active crypto # mapping? enumerate_luks # Look for all iscsi disks for _host_dir in /sys/devices/platform/host* /sys/devices/pci*/*/*/host* ; do if ! [ -d "$_host_dir"/iscsi_host* ] || ! [ -d "$_host_dir"/iscsi_host/host* ] ; then continue fi for _session_dir in "$_host_dir"/session* ; do [ -d "$_session_dir"/target* ] || continue for _block_dev_dir in "$_session_dir"/target*/*\:*/block/* ; do _block_dev=${_block_dev_dir##*/} [ x"${_block_dev}"x != x"*"x ] || continue add_to_set iscsi_disks "${_block_dev}" hash_add_to_set ISCSI_DEVICE_SESSIONS "${_block_dev}" ${_session_dir} done done done # Look for all partitions on those disks for _disk in $iscsi_disks ; do hash_get _disk_sessions ISCSI_DEVICE_SESSIONS "${_disk}" for _part_dir in /sys/class/block/"${_disk}"/"${_disk}"?* ; do _part="${_part_dir##*/}" [ x"${_part}"x != x"${_disk}?*"x ] || continue add_to_set iscsi_partitions "${_part}" hash_set ISCSI_DEVICE_SESSIONS "${_part}" "${_disk_sessions}" done done if [ -x $MULTIPATH ] ; then # Look for all multipath disks for _disk in $iscsi_disks ; do hash_get _disk_sessions ISCSI_DEVICE_SESSIONS "${_disk}" for _alias in $($MULTIPATH -v1 -l /dev/"$_disk") ; do _mp_dev="$(readlink -fe "/dev/mapper/${_alias}" || :)" [ -n "${_mp_dev}" ] || continue add_to_set iscsi_multipath_disks "${_mp_dev#/dev/}" add_to_set iscsi_multipath_disk_aliases "${_alias}" hash_add_to_set ISCSI_DEVICE_SESSIONS "${_mp_dev#/dev/}" ${_disk_sessions} hash_add_to_set ISCSI_MPALIAS_SESSIONS "${_alias}" ${_disk_sessions} done done # Look for partitions on these multipath disks for _alias in $iscsi_multipath_disk_aliases ; do hash_get _mp_sessions ISCSI_MPALIAS_SESSIONS "${_alias}" for _part_name in /dev/mapper/"${_alias}"-part* ; do _part="$(readlink -fe "$_part_name" 2>/dev/null || :)" [ -n "${_part}" ] || continue add_to_set iscsi_multipath_partitions "${_part#/dev/}" hash_set ISCSI_DEVICE_SESSIONS "${_part#/dev/}" "${_mp_sessions}" done done fi if [ $HAVE_LUKS -eq 1 ] ; then # Look for all LUKS devices. for _dev in $iscsi_disks $iscsi_partitions $iscsi_multipath_disks $iscsi_multipath_partitions ; do hash_get _luksDev LUKS_DEVICES_REVERSE_MAP "${_dev}" [ -n "${_luksDev}" ] || continue add_to_set iscsi_luks_pass1 "${_luksDev}" hash_get _currentSession ISCSI_DEVICE_SESSIONS "${_dev}" if [ -n "${_currentSession}" ] ; then hash_set ISCSI_DEVICE_SESSIONS "${_luksDev}" "${_currentSession}" fi done fi if [ $HAVE_LVM -eq 1 ] ; then # Look for all LVM volume groups that have a backing store # on any iSCSI device we found. Also, add $LVMGROUPS set in # /etc/default/open-iscsi (for more complicated stacking # configurations we don't automatically detect). for _vg in $(get_lvm_vgs $iscsi_disks $iscsi_partitions $iscsi_multipath_disks $iscsi_multipath_partitions $iscsi_luks_pass1) $LVMGROUPS ; do add_to_set iscsi_lvm_vgs "$_vg" done # $iscsi_lvm_vgs is now unique list for _vg in $iscsi_lvm_vgs ; do # get PVs to track iSCSI sessions for _pv in $($VGS --noheadings -o pv_name "$_vg" 2>/dev/null) ; do _pv_dev="$(readlink -fe "$_pv" 2>/dev/null || :)" [ -n "${_pv_dev}" ] || continue hash_get _pv_sessions ISCSI_DEVICE_SESSIONS "${_pv_dev#/dev/}" hash_add_to_set ISCSI_LVMVG_SESSIONS "${_vg}" ${_pv_sessions} done # now we collected all sessions belonging to this VG hash_get _vg_sessions ISCSI_LVMVG_SESSIONS "${_vg}" # find all LVs for _lv in $($VGS --noheadings -o lv_name "$_vg" 2>/dev/null) ; do _dev="$(readlink -fe "/dev/${_vg}/${_lv}" 2>/dev/null || :)" [ -n "${_dev}" ] || continue iscsi_lvm_lvs="$iscsi_lvm_lvs ${_dev#/dev/}" hash_set ISCSI_DEVICE_SESSIONS "${_dev#/dev/}" "${_vg_sessions}" done done fi if [ $HAVE_LUKS -eq 1 ] ; then # Look for all LUKS devices. for _dev in $iscsi_lvm_lvs ; do hash_get _luksDev LUKS_DEVICES_REVERSE_MAP "${_dev}" [ -n "${_luksDev}" ] || continue add_to_set iscsi_luks_pass2 "${_luksDev}" hash_get _currentSession ISCSI_DEVICE_SESSIONS "${_dev}" if [ -n "${_currentSession}" ] ; then hash_set ISCSI_DEVICE_SESSIONS "${_luksDev}" "${_currentSession}" fi done fi # Gather together all mount sources iscsi_potential_mount_sources="$iscsi_potential_mount_sources $iscsi_disks $iscsi_partitions" iscsi_potential_mount_sources="$iscsi_potential_mount_sources $iscsi_multipath_disks $iscsi_multipath_partitions" iscsi_potential_mount_sources="$iscsi_potential_mount_sources $iscsi_lvm_lvs" iscsi_potential_mount_sources="$iscsi_potential_mount_sources $iscsi_luks_pass1 $iscsi_luks_pass2" # Convert them to numerical representation iscsi_potential_mount_sources_majmin="" for _src in $iscsi_potential_mount_sources ; do device_majmin _src_majmin "$_src" [ -n "$_src_majmin" ] || continue iscsi_potential_mount_sources_majmin="${iscsi_potential_mount_sources_majmin} ${_src_majmin}" hash_get _dev_sessions ISCSI_DEVICE_SESSIONS "${_src}" hash_set ISCSI_NUMDEVICE_SESSIONS "${_src_majmin}" "${_dev_sessions}" done # Enumerate mount points iscsi_mount_points="" iscsi_mount_point_ids="" while read _mpid _mppid _mpdev _mpdevpath _mppath _mpopts _other ; do if in_set iscsi_potential_mount_sources_majmin "$_mpdev" ; then if in_set EXCLUDE_MOUNTS "${_mppath}" ; then hash_get _dev_sessions ISCSI_NUMDEVICE_SESSIONS "${_mpdev}" add_to_set ISCSI_EXCLUDED_SESSIONS $_dev_sessions continue fi # list mountpoints in reverse order (in case # some are stacked) mount --move may cause the # order of /proc/self/mountinfo to not always # reflect the stacking order, so this is not # fool-proof, but it's better than nothing iscsi_mount_points="$_mppath $iscsi_mount_points" iscsi_mount_point_ids="$_mpid $iscsi_mount_points" fi done < /proc/self/mountinfo } try_umount() { # in order to handle stacking try twice; together with the fact # that the list of mount points is in reverse order of the # contents /proc/self/mountinfo this should catch most cases for retry in 1 2 ; do for path in $iscsi_mount_points ; do # first try to see if it really is a mountpoint # still (might be the second round this is done # and the mount is already gone, or something # else umounted it first) if ! fstab-decode mountpoint -q "$path" ; then continue fi # try to umount it if ! fstab-decode umount "$path" ; then # unfortunately, umount's exit code # may be a false negative, i.e. it # might give a failure exit code, even # though it succeeded, so check again if fstab-decode mountpoint -q "$path" ; then echo "Could not unmount $path" >&2 any_umount_failed=1 fi fi done done } try_deactivate_lvm() { [ $HAVE_LVM -eq 1 ] || return for vg in $iscsi_lvm_vgs ; do vg_excluded=0 hash_get vg_sessions ISCSI_LVMVG_SESSIONS "$vg" for vg_session in $vg_sessions ; do if in_set ISCSI_EXCLUDED_SESSIONS "$vg_session" ; then vg_excluded=1 fi done if [ $vg_excluded -eq 1 ] ; then # volume group on same iSCSI session as excluded # mount, don't disable it # (FIXME: we should only exclude VGs that contain # those mounts, not also those that happen to be # in the same iSCSI session) continue fi if ! $VGCHANGE --available=n $vg ; then # Make sure the volume group (still) exists. If # it doesn't we count that as deactivated, so # don't fail then. _vg_test=$(vgs -o vg_name --noheadings $vg 2>/dev/null || :) if [ -n "${_vg_test}" ] ; then echo "Cannot deactivate Volume Group $vg" >&2 any_umount_failed=1 fi fi done } try_dismantle_multipath() { [ -x $MULTIPATH ] || return for mpalias in $iscsi_multipath_disk_aliases ; do mp_excluded=0 hash_get mp_sessions ISCSI_MPALIAS_SESSIONS "$mpalias" for mp_session in $mp_sessions ; do if in_set ISCSI_EXCLUDED_SESSIONS "$mp_session" ; then mp_excluded=1 fi done if [ $mp_excluded -eq 1 ] ; then # multipath device on same iSCSI session as # excluded mount, don't disable it # (FIXME: we should only exclude multipath mounts # that contain those mounts, not also those that # happen to be in the same iSCSI session) continue fi if ! $MULTIPATH -f $mpalias ; then echo "Cannot dismantle Multipath Device $mpalias" >&2 any_umount_failed=1 fi done } try_dismantle_luks() { [ $HAVE_LUKS -eq 1 ] || return case "$1" in 1) iscsi_luks_current_pass="$iscsi_luks_pass1" ;; 2|*) iscsi_luks_current_pass="$iscsi_luks_pass2" ;; esac for luksDev in $iscsi_luks_current_pass ; do luks_excluded=0 hash_get device_sessions ISCSI_DEVICE_SESSIONS "$luksDev" for device_session in $device_sessions ; do if in_set ISCSI_EXCLUDED_SESSIONS "$device_session" ; then luks_excluded=1 fi done if [ $luks_excluded -eq 1 ] ; then continue fi _luksName="$($DMSETUP info -c --noheadings -o name /dev/"$luksDev" 2>/dev/null || :)" [ -n "${_luksName}" ] || continue if ! $CRYPTSETUP close "${_luksName}" ; then echo "Cannot dismantle cryptsetup device ${_luksName}" >&2 any_umount_failed=1 fi done } # Don't do this if we are using systemd as init system, since systemd # takes care of network filesystems (including those marked _netdev) by # itself. if ! [ -d /run/systemd/system ] && [ $HANDLE_NETDEV -eq 1 ] && [ $DRY_RUN -eq 0 ]; then echo "Unmounting all devices marked _netdev"; umount -a -O _netdev >/dev/null 2>&1 fi enumerate_iscsi_devices # Dry run? Just print what we want to do (useful for administrator to check). if [ $DRY_RUN -eq 1 ] ; then echo "$0: would umount the following mount points:" had_mount=0 if [ -n "$iscsi_mount_points" ] ; then for v in $iscsi_mount_points ; do echo " $v" had_mount=1 done fi [ $had_mount -eq 1 ] || echo " (none)" echo "$0: would disable the following LUKS devices (second pass):" had_luks=0 if [ -n "$iscsi_luks_pass2" ] ; then for v in ${iscsi_luks_pass2} ; do luks_excluded=0 hash_get device_sessions ISCSI_DEVICE_SESSIONS "$v" for device_session in $device_sessions ; do if in_set ISCSI_EXCLUDED_SESSIONS "$device_session" ; then luks_excluded=1 fi done if [ $luks_excluded -eq 1 ] ; then continue fi _luksName="$($DMSETUP info -c --noheadings -o name /dev/"$v" 2>/dev/null || :)" [ -n "${_luksName}" ] || continue echo " ${_luksName}" had_luks=1 done fi [ $had_luks -eq 1 ] || echo " (none)" echo "$0: would deactivate the following LVM Volume Groups:" had_vg=0 if [ -n "$iscsi_lvm_vgs" ] ; then for v in $iscsi_lvm_vgs ; do # sync this exclusion logic with try_deactivate_lvm vg_excluded=0 hash_get vg_sessions ISCSI_LVMVG_SESSIONS "$v" for vg_session in $vg_sessions ; do if in_set ISCSI_EXCLUDED_SESSIONS "$vg_session" ; then vg_excluded=1 fi done if [ $vg_excluded -eq 1 ] ; then continue fi echo " $v" had_vg=1 done fi [ $had_vg -eq 1 ] || echo " (none)" echo "$0: would disable the following LUKS devices (first pass):" had_luks=0 if [ -n "$iscsi_luks_pass1" ] ; then for v in ${iscsi_luks_pass1} ; do luks_excluded=0 hash_get device_sessions ISCSI_DEVICE_SESSIONS "$v" for device_session in $device_sessions ; do if in_set ISCSI_EXCLUDED_SESSIONS "$device_session" ; then luks_excluded=1 fi done if [ $luks_excluded -eq 1 ] ; then continue fi _luksName="$($DMSETUP info -c --noheadings -o name /dev/"$v" 2>/dev/null || :)" [ -n "${_luksName}" ] || continue echo " ${_luksName}" had_luks=1 done fi [ $had_luks -eq 1 ] || echo " (none)" echo "$0: would deactivate the following multipath volumes:" had_mp=0 if [ -n "$iscsi_multipath_disk_aliases" ] ; then for v in $iscsi_multipath_disk_aliases ; do # sync this exclusion logic with try_dismantle_multipath mp_excluded=0 hash_get mp_sessions ISCSI_MPALIAS_SESSIONS "$v" for mp_session in $mp_sessions ; do if in_set ISCSI_EXCLUDED_SESSIONS "$mp_session" ; then mp_excluded=1 fi done if [ $mp_excluded -eq 1 ] ; then continue fi echo " $v" had_mp=1 done fi [ $had_mp -eq 1 ] || echo " (none)" if [ -n "$ISCSI_EXCLUDED_SESSIONS" ] ; then echo "$0: the following sessions are excluded from disconnection (because / or another excluded mount is on them):" for v in $ISCSI_EXCLUDED_SESSIONS ; do echo " $v" done fi exit 0 fi # after our first enumeration, write out a list of sessions that # shouldn't be terminated because excluded mounts are on those # sessions if [ -n "$ISCSI_EXCLUDED_SESSIONS" ] ; then mkdir -p -m 0700 /run/open-iscsi for session in $ISCSI_EXCLUDED_SESSIONS ; do printf '%s\n' $session done > /run/open-iscsi/shutdown-keep-sessions else # make sure there's no leftover from a previous call rm -f /run/open-iscsi/shutdown-keep-sessions fi any_umount_failed=0 try_umount try_dismantle_luks 2 try_deactivate_lvm try_dismantle_luks 1 try_dismantle_multipath while [ $any_umount_failed -ne 0 ] && ( [ $timeout -gt 0 ] || [ $timeout -eq -1 ] ) ; do # wait a bit, perhaps there was still a program that # was terminating sleep 1 # try again and decrease timeout enumerate_iscsi_devices any_umount_failed=0 try_umount try_dismantle_luks 2 try_deactivate_lvm try_dismantle_luks 1 try_dismantle_multipath if [ $timeout -gt 0 ] ; then timeout=$((timeout - 1)) fi done # Create signaling file (might be useful) if [ $any_umount_failed -eq 1 ] ; then touch /run/open-iscsi/some_umount_failed else rm -f /run/open-iscsi/some_umount_failed fi exit $any_umount_failed