From 39d90012a652fa4d9d2534d0168ddad8cacec248 Mon Sep 17 00:00:00 2001
From: Kairui Song <kasong@redhat.com>
Date: Thu, 10 Sep 2020 02:18:02 +0800
Subject: [PATCH] 04watchdog: split the watchdog module install

In some cases, user only want to include the watchdog module, not the
wdctl or any other userspace helper. For example, systemd have a
RebootWatchdogSec option that use watchdog to prevent reboot hangs. And
it can help prevent machines hangs when reboot directly within the
initramfs stage. So split the module installation to a standlone module.

Also when watchdog-module get included, install driver for all loaded
watchdog instaed of only install driver for active watchdog. Both
watchdog and watchdog-module return 255 in check(), so it's enabled only
when manually included, the watchdog may get configured/activated later.

Signed-off-by: Kairui Song <kasong@redhat.com>
---
 modules.d/04watchdog-modules/module-setup.sh | 61 ++++++++++++++++++++++++++++
 modules.d/04watchdog/module-setup.sh         | 50 +----------------------
 2 files changed, 63 insertions(+), 48 deletions(-)

diff --git a/modules.d/04watchdog-modules/module-setup.sh b/modules.d/04watchdog-modules/module-setup.sh
new file mode 100755
index 00000000..5fbd769b
--- /dev/null
+++ b/modules.d/04watchdog-modules/module-setup.sh
@@ -0,0 +1,61 @@
+#!/bin/bash
+
+# called by dracut
+check() {
+    return 255
+}
+
+# called by dracut
+depends() {
+    return 0
+}
+
+# called by dracut
+install() {
+    return 0
+}
+
+installkernel() {
+    local -A _drivers
+    local _alldrivers _wdtdrv _wdtppath _dir
+    [[ -d /sys/class/watchdog/ ]] || return
+    for _dir in /sys/class/watchdog/*; do
+        [[ -d "$_dir" ]] || continue
+        [[ -f "$_dir/state" ]] || continue
+        # device/modalias will return driver of this device
+        _wdtdrv=$(< "$_dir/device/modalias")
+        # There can be more than one module represented by same
+        # modalias. Currently load all of them.
+        # TODO: Need to find a way to avoid any unwanted module
+        # represented by modalias
+        _wdtdrv=$(modprobe --set-version "$kernel" -R $_wdtdrv 2>/dev/null)
+        if [[ $_wdtdrv ]]; then
+            instmods $_wdtdrv
+            for i in $_wdtdrv; do
+                _drivers[$i]=1
+            done
+        fi
+        # however in some cases, we also need to check that if there is
+        # a specific driver for the parent bus/device.  In such cases
+        # we also need to enable driver for parent bus/device.
+        _wdtppath=$(readlink -f "$_dir/device")
+        while [[ -d "$_wdtppath" ]] && [[ "$_wdtppath" != "/sys" ]]; do
+            _wdtppath=$(readlink -f "$_wdtppath/..")
+            [[ -f "$_wdtppath/modalias" ]] || continue
+
+            _wdtdrv=$(< "$_wdtppath/modalias")
+            _wdtdrv=$(modprobe --set-version "$kernel" -R $_wdtdrv 2>/dev/null)
+            if [[ $_wdtdrv ]]; then
+                instmods $_wdtdrv
+                for i in $_wdtdrv; do
+                    _drivers[$i]=1
+                done
+            fi
+        done
+    done
+    # ensure that watchdog module is loaded as early as possible
+    _alldrivers="${!_drivers[*]}"
+    [[ $_alldrivers ]] && echo "rd.driver.pre=${_alldrivers// /,}" > ${initdir}/etc/cmdline.d/00-watchdog.conf
+
+    return 0
+}
diff --git a/modules.d/04watchdog/module-setup.sh b/modules.d/04watchdog/module-setup.sh
index 7566d651..15bcd897 100755
--- a/modules.d/04watchdog/module-setup.sh
+++ b/modules.d/04watchdog/module-setup.sh
@@ -7,7 +7,7 @@ check() {
 
 # called by dracut
 depends() {
-    return 0
+    return "watchdog-modules"
 }
 
 # called by dracut
@@ -27,53 +27,7 @@ install() {
         inst_hook cleanup   00 "$moddir/watchdog.sh"
         inst_hook cleanup   99 "$moddir/watchdog.sh"
     fi
+
     inst_hook emergency 02 "$moddir/watchdog-stop.sh"
     inst_multiple -o wdctl
 }
-
-installkernel() {
-    local -A _drivers
-    local _alldrivers _active _wdtdrv _wdtppath _dir
-    [[ -d /sys/class/watchdog/ ]] || return
-    for _dir in /sys/class/watchdog/*; do
-        [[ -d "$_dir" ]] || continue
-        [[ -f "$_dir/state" ]] || continue
-        _active=$(< "$_dir/state")
-        ! [[ $hostonly ]] || [[ "$_active" =  "active" ]] || continue
-        # device/modalias will return driver of this device
-        _wdtdrv=$(< "$_dir/device/modalias")
-        # There can be more than one module represented by same
-        # modalias. Currently load all of them.
-        # TODO: Need to find a way to avoid any unwanted module
-        # represented by modalias
-        _wdtdrv=$(modprobe --set-version "$kernel" -R $_wdtdrv 2>/dev/null)
-        if [[ $_wdtdrv ]]; then
-            instmods $_wdtdrv
-            for i in $_wdtdrv; do
-                _drivers[$i]=1
-            done
-        fi
-        # however in some cases, we also need to check that if there is
-        # a specific driver for the parent bus/device.  In such cases
-        # we also need to enable driver for parent bus/device.
-        _wdtppath=$(readlink -f "$_dir/device")
-        while [[ -d "$_wdtppath" ]] && [[ "$_wdtppath" != "/sys" ]]; do
-            _wdtppath=$(readlink -f "$_wdtppath/..")
-            [[ -f "$_wdtppath/modalias" ]] || continue
-
-            _wdtdrv=$(< "$_wdtppath/modalias")
-            _wdtdrv=$(modprobe --set-version "$kernel" -R $_wdtdrv 2>/dev/null)
-            if [[ $_wdtdrv ]]; then
-                instmods $_wdtdrv
-                for i in $_wdtdrv; do
-                    _drivers[$i]=1
-                done
-            fi
-        done
-    done
-    # ensure that watchdog module is loaded as early as possible
-    _alldrivers="${!_drivers[*]}"
-    [[ $_alldrivers ]] && echo "rd.driver.pre=${_alldrivers// /,}" > ${initdir}/etc/cmdline.d/00-watchdog.conf
-
-    return 0
-}