zfs-builds-mm/zfs-0.8.1/cmd/zed/zed.d/history_event-zfs-list-cacher.sh.in
2019-07-06 23:40:11 +02:00

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#!/bin/sh
#
# Track changes to enumerated pools for use in early-boot
set -ef
FSLIST_DIR="@sysconfdir@/zfs/zfs-list.cache"
FSLIST_TMP="@runstatedir@/zfs-list.cache.new"
FSLIST="${FSLIST_DIR}/${ZEVENT_POOL}"
# If the pool specific cache file is not writeable, abort
[ -w "${FSLIST}" ] || exit 0
[ -f "${ZED_ZEDLET_DIR}/zed.rc" ] && . "${ZED_ZEDLET_DIR}/zed.rc"
. "${ZED_ZEDLET_DIR}/zed-functions.sh"
zed_exit_if_ignoring_this_event
zed_check_cmd "${ZFS}" sort diff grep
# If we are acting on a snapshot, we have nothing to do
printf '%s' "${ZEVENT_HISTORY_DSNAME}" | grep '@' && exit 0
# We obtain a lock on zfs-list to avoid any simultaneous writes.
# If we run into trouble, log and drop the lock
abort_alter() {
zed_log_msg "Error updating zfs-list.cache!"
zed_unlock zfs-list
}
finished() {
zed_unlock zfs-list
trap - EXIT
exit 0
}
case "${ZEVENT_HISTORY_INTERNAL_NAME}" in
create|"finish receiving"|import|destroy|rename)
;;
export)
zed_lock zfs-list
trap abort_alter EXIT
echo > "${FSLIST}"
finished
;;
set|inherit)
# Only act if one of the tracked properties is altered.
case "${ZEVENT_HISTORY_INTERNAL_STR%%=*}" in
canmount|mountpoint|atime|relatime|devices|exec| \
readonly|setuid|nbmand) ;;
*) exit 0 ;;
esac
;;
*)
# Ignore all other events.
exit 0
;;
esac
zed_lock zfs-list
trap abort_alter EXIT
PROPS="name,mountpoint,canmount,atime,relatime,devices,exec,readonly"
PROPS="${PROPS},setuid,nbmand"
"${ZFS}" list -H -t filesystem -o $PROPS -r "${ZEVENT_POOL}" > "${FSLIST_TMP}"
# Sort the output so that it is stable
sort "${FSLIST_TMP}" -o "${FSLIST_TMP}"
# Don't modify the file if it hasn't changed
diff -q "${FSLIST_TMP}" "${FSLIST}" || mv "${FSLIST_TMP}" "${FSLIST}"
rm -f "${FSLIST_TMP}"
finished