Hi, Kairui
Thanks for your comment.
在 2020年10月26日 16:04, Kairui Song 写道:
On Tue, Oct 20, 2020 at 10:46 AM Lianbo Jiang
<lijiang(a)redhat.com> wrote:
>
> Currently, all messages are directly printed to the console, sometimes,
> we also need to output these messages to the journal log according to
> the log level.
>
> In view of this, introduce the kdump logger from the dracut module.
>
> Signed-off-by: Lianbo Jiang <lijiang(a)redhat.com>
> ---
> kdump-logger.sh | 344 ++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 344 insertions(+)
> create mode 100755 kdump-logger.sh
>
> diff --git a/kdump-logger.sh b/kdump-logger.sh
> new file mode 100755
> index 000000000000..c2c5c35820e1
> --- /dev/null
> +++ b/kdump-logger.sh
> @@ -0,0 +1,344 @@
> +#!/bin/bash
> +#
> +# This comes from the dracut-logger.sh
> +#
> +# The logger defined 6 logging levels:
> +# - dtrace() (6)
> +# The TRACE Level designates finer-grained informational events than the
> +# DEBUG.
> +# - ddebug (5)
> +# The DEBUG Level designates fine-grained informational events that are most
> +# useful to debug an application.
> +# - dinfo (4)
> +# The INFO level designates informational messages that highlight the
> +# progress of the application at coarse-grained level.
> +# - dwarn (3)
> +# The WARN level designates potentially harmful situations.
> +# - derror (2)
> +# The ERROR level designates error events that might still allow the
> +# application to continue running.
> +# - dfatal (1)
> +# The FATAL level designates very severe error events that will presumably
> +# lead the application to abort.
> +#
> +# Logging is controlled by following global variables:
> +# - @var kdump_stdloglvl - logging level to standard error (console output)
> +# - @var kdump_sysloglvl - logging level to syslog (by logger command)
> +# - @var kdump_kmsgloglvl - logging level to /dev/kmsg (only for boot-time)
> +#
> +# If any of the variables is not set, this function set it to default:
> +# - @var kdump_stdloglvl = 4 (info)
> +# - @var kdump_sysloglvl = 4 (info)
> +# - @var kdump_kmsgloglvl = 0 (no logging)
> +#
> +# First of all you have to start with dlog_init() function which initializes
> +# required variables. Don't call any other logging function before that one!
> +#
> +# @brief Initializes Logger.
> +# @retval 1 if something has gone wrong
> +# @retval 0 on success.
> +#
> +dlog_init() {
> + local ret=0; local errmsg
> + [ -z "$kdump_stdloglvl" ] && kdump_stdloglvl=4
> + [ -z "$kdump_sysloglvl" ] && kdump_sysloglvl=4
> + [ -z "$kdump_kmsgloglvl" ] && kdump_kmsgloglvl=0
> + # Skip initialization if it's already done.
> + [ -n "$kdump_maxloglvl" ] && return 0
> +
> + if [[ $UID -ne 0 ]]; then
> + kdump_kmsgloglvl=0
> + kdump_sysloglvl=0
> + fi
> +
> + if [[ $kdump_sysloglvl -gt 0 ]]; then
> + if [[ -d /run/systemd/journal ]] \
> + && type -P systemd-cat &>/dev/null \
> + && systemctl --quiet is-active systemd-journald.socket
&>/dev/null; then
> + readonly _systemdcatfile="/var/tmp/systemd-cat"
> + mkfifo "$_systemdcatfile" &>/dev/null
> + readonly _dlogfd=15
> + systemd-cat -t 'kdump' --level-prefix=true
<"$_systemdcatfile" &
> + exec 15>"$_systemdcatfile"
> + elif ! [ -S /dev/log -a -w /dev/log ] || ! command -v logger >/dev/null;
then
> + # We cannot log to syslog, so turn this facility off.
> + kdump_kmsgloglvl=$kdump_sysloglvl
> + kdump_sysloglvl=0
> + ret=1
> + errmsg="No '/dev/log' or 'logger' included for
syslog logging"
> + fi
> + fi
> +
> + if [[ $kdump_sysloglvl -gt 0 ]] || [[ $kdump_kmsgloglvl -gt 0 ]]; then
> + if [ -n "$dracutbasedir" ]; then
Hi Lianbo, I think this dracut related code should be dropped.
From dracut comment, syslogfacility is set either to 'user' (when
building initramfs) or 'daemon' (when booting).
I thin we can either just drop it, as usually we already know where
the log comes from, or maybe we can use /proc/vmcore to judge if it's
the kdump kernel.
Good idea. I will replace it with the following condition:
[ -s /proc/vmcore ] && echo $((24+$lvl)) || echo $((8+$lvl))
Thanks.
Lianbo
> + readonly kdump_syslogfacility=user
> + else
> + readonly kdump_syslogfacility=daemon
> + fi
> + export kdump_syslogfacility
> + fi
> +
> + local lvl; local maxloglvl_l=0
> + for lvl in $kdump_stdloglvl $kdump_sysloglvl $kdump_kmsgloglvl; do
> + [[ $lvl -gt $maxloglvl_l ]] && maxloglvl_l=$lvl
> + done
> + readonly kdump_maxloglvl=$maxloglvl_l
> + export kdump_maxloglvl
> +
> +
> + if [[ $kdump_stdloglvl -lt 6 ]] && [[ $kdump_kmsgloglvl -lt 6 ]]
&& [[ $kdump_sysloglvl -lt 6 ]]; then
> + unset dtrace
> + dtrace() { :; };
> + fi
> +
> + if [[ $kdump_stdloglvl -lt 5 ]] && [[ $kdump_kmsgloglvl -lt 5 ]]
&& [[ $kdump_sysloglvl -lt 5 ]]; then
> + unset ddebug
> + ddebug() { :; };
> + fi
> +
> + if [[ $kdump_stdloglvl -lt 4 ]] && [[ $kdump_kmsgloglvl -lt 4 ]]
&& [[ $kdump_sysloglvl -lt 4 ]]; then
> + unset dinfo
> + dinfo() { :; };
> + fi
> +
> + if [[ $kdump_stdloglvl -lt 3 ]] && [[ $kdump_kmsgloglvl -lt 3 ]]
&& [[ $kdump_sysloglvl -lt 3 ]]; then
> + unset dwarn
> + dwarn() { :; };
> + unset dwarning
> + dwarning() { :; };
> + fi
> +
> + if [[ $kdump_stdloglvl -lt 2 ]] && [[ $kdump_kmsgloglvl -lt 2 ]]
&& [[ $kdump_sysloglvl -lt 2 ]]; then
> + unset derror
> + derror() { :; };
> + fi
> +
> + if [[ $kdump_stdloglvl -lt 1 ]] && [[ $kdump_kmsgloglvl -lt 1 ]]
&& [[ $kdump_sysloglvl -lt 1 ]]; then
> + unset dfatal
> + dfatal() { :; };
> + fi
> +
> + [ -n "$errmsg" ] && derror "$errmsg"
> +
> + return $ret
> +}
> +
> +## @brief Converts numeric logging level to the first letter of level name.
> +#
> +# @param lvl Numeric logging level in range from 1 to 6.
> +# @retval 1 if @a lvl is out of range.
> +# @retval 0 if @a lvl is correct.
> +# @result Echoes first letter of level name.
> +_lvl2char() {
> + case "$1" in
> + 1) echo F;;
> + 2) echo E;;
> + 3) echo W;;
> + 4) echo I;;
> + 5) echo D;;
> + 6) echo T;;
> + *) return 1;;
> + esac
> +}
> +
> +## @brief Converts numeric level to logger priority defined by POSIX.2.
> +#
> +# @param lvl Numeric logging level in range from 1 to 6.
> +# @retval 1 if @a lvl is out of range.
> +# @retval 0 if @a lvl is correct.
> +# @result Echoes logger priority.
> +_lvl2syspri() {
> + printf $kdump_syslogfacility.
> + case "$1" in
> + 1) echo crit;;
> + 2) echo error;;
> + 3) echo warning;;
> + 4) echo info;;
> + 5) echo debug;;
> + 6) echo debug;;
> + *) return 1;;
> + esac
> +}
> +
> +## @brief Converts logger numeric level to syslog log level
> +#
> +# @param lvl Numeric logging level in range from 1 to 6.
> +# @retval 1 if @a lvl is out of range.
> +# @retval 0 if @a lvl is correct.
> +# @result Echoes kernel console numeric log level
> +#
> +# Conversion is done as follows:
> +#
> +# <tt>
> +# none -> LOG_EMERG (0)
> +# none -> LOG_ALERT (1)
> +# FATAL(1) -> LOG_CRIT (2)
> +# ERROR(2) -> LOG_ERR (3)
> +# WARN(3) -> LOG_WARNING (4)
> +# none -> LOG_NOTICE (5)
> +# INFO(4) -> LOG_INFO (6)
> +# DEBUG(5) -> LOG_DEBUG (7)
> +# TRACE(6) /
> +# </tt>
> +#
> +# @see /usr/include/sys/syslog.h
> +_dlvl2syslvl() {
> + local lvl
> +
> + case "$1" in
> + 1) lvl=2;;
> + 2) lvl=3;;
> + 3) lvl=4;;
> + 4) lvl=6;;
> + 5) lvl=7;;
> + 6) lvl=7;;
> + *) return 1;;
> + esac
> +
> + [ "$kdump_syslogfacility" = user ] && echo $((8+$lvl)) || echo
$((24+$lvl))
> +}
> +
> +## @brief Prints to stderr and/or writes to file, to syslog and/or /dev/kmsg
> +# given message with given level (priority).
> +#
> +# @param lvl Numeric logging level.
> +# @param msg Message.
> +# @retval 0 It's always returned, even if logging failed.
> +#
> +# @note This function is not supposed to be called manually. Please use
> +# dtrace(), ddebug(), or others instead which wrap this one.
> +#
> +# This is core logging function which logs given message to standard error, file
> +# and/or syslog (with POSIX shell command <tt>logger</tt>) and/or to
/dev/kmsg.
> +# The format is following:
> +#
> +# <tt>X: some message</tt>
> +#
> +# where @c X is the first letter of logging level. See module description for
> +# details on that.
> +#
> +# Message to syslog is sent with tag @c kdump. Priorities are mapped as
> +# following:
> +# - @c FATAL to @c crit
> +# - @c ERROR to @c error
> +# - @c WARN to @c warning
> +# - @c INFO to @c info
> +# - @c DEBUG and @c TRACE both to @c debug
> +_do_dlog() {
> + local lvl="$1"; shift
> + local lvlc=$(_lvl2char "$lvl") || return 0
> + local msg="$*"
> + local lmsg="$lvlc: $*"
> +
> + [[ $lvl -le $kdump_stdloglvl ]] && printf -- 'kdump: %s\n'
"$msg" >&2
> +
> + if [[ $lvl -le $kdump_sysloglvl ]]; then
> + if [[ "$_dlogfd" ]]; then
> + printf -- "<%s>%s\n" "$(($(_dlvl2syslvl $lvl) &
7))" "$msg" >&$_dlogfd
> + else
> + logger -t "kdump[$$]" -p $(_lvl2syspri $lvl) --
"$msg"
> + fi
> + fi
> +
> + [[ $lvl -le $kdump_kmsgloglvl ]] && \
> + echo "<$(_dlvl2syslvl $lvl)>kdump[$$] $msg" >/dev/kmsg
> +}
> +
> +## @brief Internal helper function for _do_dlog()
> +#
> +# @param lvl Numeric logging level.
> +# @param msg Message.
> +# @retval 0 It's always returned, even if logging failed.
> +#
> +# @note This function is not supposed to be called manually. Please use
> +# dtrace(), ddebug(), or others instead which wrap this one.
> +#
> +# This function calls _do_dlog() either with parameter msg, or if
> +# none is given, it will read standard input and will use every line as
> +# a message.
> +#
> +# This enables:
> +# dwarn "This is a warning"
> +# echo "This is a warning" | dwarn
> +dlog() {
> + [ -z "$kdump_maxloglvl" ] && return 0
> + [[ $1 -le $kdump_maxloglvl ]] || return 0
> +
> + if [[ $# -gt 1 ]]; then
> + _do_dlog "$@"
> + else
> + while read line || [ -n "$line" ]; do
> + _do_dlog "$1" "$line"
> + done
> + fi
> +}
> +
> +## @brief Logs message at TRACE level (6)
> +#
> +# @param msg Message.
> +# @retval 0 It's always returned, even if logging failed.
> +dtrace() {
> + set +x
> + dlog 6 "$@"
> + [ -n "$debug" ] && set -x || :
> +}
> +
> +## @brief Logs message at DEBUG level (5)
> +#
> +# @param msg Message.
> +# @retval 0 It's always returned, even if logging failed.
> +ddebug() {
> + set +x
> + dlog 5 "$@"
> + [ -n "$debug" ] && set -x || :
> +}
> +
> +## @brief Logs message at INFO level (4)
> +#
> +# @param msg Message.
> +# @retval 0 It's always returned, even if logging failed.
> +dinfo() {
> + set +x
> + dlog 4 "$@"
> + [ -n "$debug" ] && set -x || :
> +}
> +
> +## @brief Logs message at WARN level (3)
> +#
> +# @param msg Message.
> +# @retval 0 It's always returned, even if logging failed.
> +dwarn() {
> + set +x
> + dlog 3 "$@"
> + [ -n "$debug" ] && set -x || :
> +}
> +
> +## @brief It's an alias to dwarn() function.
> +#
> +# @param msg Message.
> +# @retval 0 It's always returned, even if logging failed.
> +dwarning() {
> + set +x
> + dwarn "$@"
> + [ -n "$debug" ] && set -x || :
> +}
> +
> +## @brief Logs message at ERROR level (2)
> +#
> +# @param msg Message.
> +# @retval 0 It's always returned, even if logging failed.
> +derror() {
> + set +x
> + dlog 2 "$@"
> + [ -n "$debug" ] && set -x || :
> +}
> +
> +## @brief Logs message at FATAL level (1)
> +#
> +# @param msg Message.
> +# @retval 0 It's always returned, even if logging failed.
> +dfatal() {
> + set +x
> + dlog 1 "$@"
> + [ -n "$debug" ] && set -x || :
> +}
> --
> 2.17.1
>
--
Best Regards,
Kairui Song