From 9d787df19674937e8c07bd295b5d282a63829209 Mon Sep 17 00:00:00 2001
From: Baoquan He <bhe@redhat.com>
Date: Fri, 29 Mar 2013 18:36:16 +0800
Subject: [PATCH] Let user specify the action after fail

Currently the default action is emergency_shell when failure happened
during system boot. In kdump, this default may not be expected. E.g,
if dump target is not rootfs, it does not matter if mount root failed.
Adding an action which allow dracut always go ahead though failure
happens is needed by kdump.

So here add a function action_on_fail() and cmdline parameter
action_on_fail=<shell | continue>. Use action_to_fail() to replace
emergency_shell which was called after failure. By $(getarg action_on_fail=),
decide to drop into shell, or to leave away the failure and go ahead.

v3->v4:
add handling of selinux policy loaded failure, and change code format to
be consitent

Signed-off-by: Baoquan He <bhe@redhat.com>

[Edited by harald@redhat.com]
---
 dracut.cmdline.7.asc                      |  4 ++++
 modules.d/95rootfs-block/mount-root.sh    |  2 +-
 modules.d/98selinux/selinux-loadpolicy.sh |  6 ++----
 modules.d/98systemd/dracut-initqueue.sh   |  2 +-
 modules.d/98systemd/dracut-mount.sh       |  2 +-
 modules.d/98usrmount/mount-usr.sh         |  4 ++--
 modules.d/99base/dracut-lib.sh            | 22 ++++++++++++++++++++++
 modules.d/99base/init.sh                  | 12 ++++++------
 8 files changed, 39 insertions(+), 15 deletions(-)

diff --git a/dracut.cmdline.7.asc b/dracut.cmdline.7.asc
index f1457d5..4626279 100644
--- a/dracut.cmdline.7.asc
+++ b/dracut.cmdline.7.asc
@@ -121,6 +121,10 @@ Misc
    specify the controlling terminal for the console.
    This is useful, if you have multiple "console=" arguments.
 
+**action_on_fail=**_{shell|continue}_::
+   Specify the action after failure. By default it's emergency_shell.
+   'continue' means: ignore the current failure and go ahead.
+
 [[dracutkerneldebug]]
 Debug
 ~~~~~
diff --git a/modules.d/95rootfs-block/mount-root.sh b/modules.d/95rootfs-block/mount-root.sh
index c7626c3..6ed35c1 100755
--- a/modules.d/95rootfs-block/mount-root.sh
+++ b/modules.d/95rootfs-block/mount-root.sh
@@ -68,7 +68,7 @@ mount_root() {
                 warn "*** Warning -- the system did not shut down cleanly. "
                 warn "*** Dropping you to a shell; the system will continue"
                 warn "*** when you leave the shell."
-                emergency_shell
+                action_on_fail
             fi
             fsckoptions="$AUTOFSCK_OPT $fsckoptions"
         fi
diff --git a/modules.d/98selinux/selinux-loadpolicy.sh b/modules.d/98selinux/selinux-loadpolicy.sh
index d6e24d6..7526265 100755
--- a/modules.d/98selinux/selinux-loadpolicy.sh
+++ b/modules.d/98selinux/selinux-loadpolicy.sh
@@ -52,16 +52,14 @@ rd_load_policy()
         if [ $ret -eq 3 -o $permissive -eq 0 ]; then
             warn "Machine in enforcing mode."
             warn "Not continuing"
-            emergency_shell -n selinux
-            exit 1
+            action_on_fail -n selinux || exit 1
         fi
         return 0
     elif [ $permissive -eq 0 -a "$SELINUX" != "disabled" ]; then
         warn "Machine in enforcing mode and cannot execute load_policy."
         warn "To disable selinux, add selinux=0 to the kernel command line."
         warn "Not continuing"
-        emergency_shell -n selinux
-        exit 1
+        action_on_fail -n selinux || exit 1
     fi
 }
 
diff --git a/modules.d/98systemd/dracut-initqueue.sh b/modules.d/98systemd/dracut-initqueue.sh
index c6fab30..2c71bf4 100755
--- a/modules.d/98systemd/dracut-initqueue.sh
+++ b/modules.d/98systemd/dracut-initqueue.sh
@@ -62,7 +62,7 @@ while :; do
     fi
 
     main_loop=$(($main_loop+1))
-    [ $main_loop -gt $RDRETRY ] && emergency_shell "Could not boot."
+    [ $main_loop -gt $RDRETRY ] && action_on_fail "Could not boot." && break
 done
 
 unset job
diff --git a/modules.d/98systemd/dracut-mount.sh b/modules.d/98systemd/dracut-mount.sh
index 5f3d9f0..ae01512 100755
--- a/modules.d/98systemd/dracut-mount.sh
+++ b/modules.d/98systemd/dracut-mount.sh
@@ -31,7 +31,7 @@ while :; do
     done
 
     i=$(($i+1))
-    [ $i -gt 20 ] && emergency_shell "Can't mount root filesystem"
+    [ $i -gt 20 ] && action_on_fail "Can't mount root filesystem" && break
 done
 
 export -p > /dracut-state.sh
diff --git a/modules.d/98usrmount/mount-usr.sh b/modules.d/98usrmount/mount-usr.sh
index 5aaefbc..a4a66ae 100755
--- a/modules.d/98usrmount/mount-usr.sh
+++ b/modules.d/98usrmount/mount-usr.sh
@@ -42,7 +42,7 @@ fsck_usr()
             warn "*** Warning -- the system did not shut down cleanly. "
             warn "*** Dropping you to a shell; the system will continue"
             warn "*** when you leave the shell."
-            emergency_shell
+            action_on_fail
         fi
         _fsckoptions="$AUTOFSCK_OPT $_fsckoptions"
     fi
@@ -105,7 +105,7 @@ mount_usr()
             warn "Mounting /usr to $NEWROOT/usr failed"
             warn "*** Dropping you to a shell; the system will continue"
             warn "*** when you leave the shell."
-            emergency_shell
+            action_on_fail
         fi
     fi
 }
diff --git a/modules.d/99base/dracut-lib.sh b/modules.d/99base/dracut-lib.sh
index f2b16d3..1defb6f 100755
--- a/modules.d/99base/dracut-lib.sh
+++ b/modules.d/99base/dracut-lib.sh
@@ -994,6 +994,28 @@ emergency_shell()
     [ -e /run/initramfs/.die ] && exit 1
 }
 
+action_on_fail()
+{
+    local _action=$(getarg action_on_fail=)
+    case "$_action" in
+        continue)
+            [ "$1" = "-n" ] && shift 2
+            [ "$1" = "--shutdown" ] && shift 2
+            warn "$*"
+            warn "Not dropping to emergency shell, because 'action_on_fail=continue' was set on the kernel command line."
+            return 0
+            ;;
+        shell)
+            emergency_shell $@
+            return 1
+            ;;
+        *)
+            emergency_shell $@
+            return 1
+            ;;
+    esac
+}
+
 # Retain the values of these variables but ensure that they are unexported
 # This is a POSIX-compliant equivalent of bash's "export -n"
 export_n()
diff --git a/modules.d/99base/init.sh b/modules.d/99base/init.sh
index 410201a..880a2c0 100755
--- a/modules.d/99base/init.sh
+++ b/modules.d/99base/init.sh
@@ -79,7 +79,7 @@ if ! ismounted /run; then
     rm -fr /newrun
 fi
 
-trap "emergency_shell Signal caught!" 0
+trap "action_on_fail Signal caught!" 0
 
 [ -d /run/initramfs ] || mkdir -p -m 0755 /run/initramfs
 [ -d /run/log ] || mkdir -p -m 0755 /run/log
@@ -199,7 +199,7 @@ while :; do
 
     main_loop=$(($main_loop+1))
     [ $main_loop -gt $RDRETRY ] \
-        && { flock -s 9 ; emergency_shell "Could not boot."; } 9>/.console_lock
+        && { flock -s 9 ; action_on_fail "Could not boot." && break; } 9>/.console_lock
 done
 unset job
 unset queuetriggered
@@ -234,7 +234,7 @@ while :; do
 
     i=$(($i+1))
     [ $i -gt 20 ] \
-        && { flock -s 9 ; emergency_shell "Can't mount root filesystem"; } 9>/.console_lock
+        && { flock -s 9 ; action_on_fail "Can't mount root filesystem" && break; } 9>/.console_lock
 done
 
 {
@@ -268,7 +268,7 @@ done
 [ "$INIT" ] || {
     echo "Cannot find init!"
     echo "Please check to make sure you passed a valid root filesystem!"
-    emergency_shell
+    action_on_fail
 }
 
 if [ $UDEVVERSION -lt 168 ]; then
@@ -370,13 +370,13 @@ if [ -f /etc/capsdrop ]; then
 	warn "Command:"
 	warn capsh --drop=$CAPS_INIT_DROP -- -c exec switch_root "$NEWROOT" "$INIT" $initargs
 	warn "failed."
-	emergency_shell
+	action_on_fail
     }
 else
     unset RD_DEBUG
     exec $SWITCH_ROOT "$NEWROOT" "$INIT" $initargs || {
 	warn "Something went very badly wrong in the initramfs.  Please "
 	warn "file a bug against dracut."
-	emergency_shell
+	action_on_fail
     }
 fi