From 2050b6227d11ea774784b872eb457be434752af3 Mon Sep 17 00:00:00 2001
From: Adam Gelwarg <agelwarg@galileosuite.com>
Date: Mon, 11 Apr 2022 16:18:36 -0400
Subject: [PATCH] Support multipath-boot

---
 images/00-base/Dockerfile          |  2 ++
 images/00-base/multipath.conf      | 13 +++++++++++++
 images/10-kernel-stage1/Dockerfile |  1 +
 overlay/libexec/k3os/boot          |  6 ++++++
 overlay/libexec/k3os/mode-disk     | 16 ++++++++++++++++
 5 files changed, 38 insertions(+)
 create mode 100644 images/00-base/multipath.conf

diff --git a/images/00-base/Dockerfile b/images/00-base/Dockerfile
index 658b0535..a545918c 100644
--- a/images/00-base/Dockerfile
+++ b/images/00-base/Dockerfile
@@ -71,3 +71,5 @@ RUN apk --no-cache add \
 # replicate the default "no idea, friend" behavior of virt-what
  && touch /usr/sbin/virt-what \
  && chmod +x /usr/sbin/virt-what
+
+COPY multipath.conf /etc/multipath.conf
diff --git a/images/00-base/multipath.conf b/images/00-base/multipath.conf
new file mode 100644
index 00000000..507df1c7
--- /dev/null
+++ b/images/00-base/multipath.conf
@@ -0,0 +1,13 @@
+defaults {
+  find_multipaths "yes"
+  user_friendly_names "yes"
+}
+blacklist_exceptions {
+   property "(SCSI_IDENT_|ID_WWN)"
+}
+blacklist {
+    device {
+        vendor "VMware"
+        product "Virtual disk"
+    }
+}
diff --git a/images/10-kernel-stage1/Dockerfile b/images/10-kernel-stage1/Dockerfile
index d079c028..2e475bb6 100644
--- a/images/10-kernel-stage1/Dockerfile
+++ b/images/10-kernel-stage1/Dockerfile
@@ -10,6 +10,7 @@ RUN apt-get --assume-yes update \
     lz4 \
     rsync \
     xz-utils \
+    multipath-tools-boot \
  && echo 'r8152' >> /etc/initramfs-tools/modules \
  && echo 'hfs' >> /etc/initramfs-tools/modules \
  && echo 'hfsplus' >> /etc/initramfs-tools/modules \
diff --git a/overlay/libexec/k3os/boot b/overlay/libexec/k3os/boot
index 6f6b257f..d7338a92 100644
--- a/overlay/libexec/k3os/boot
+++ b/overlay/libexec/k3os/boot
@@ -44,6 +44,12 @@ setup_services()
         ln -s /etc/init.d/$i /etc/runlevels/sysinit
     done
 
+    if [ "$K3OS_MODE" = "local" ]; then
+      for i in udev-trigger multipath multipathd; do
+        ln -s /etc/init.d/$i /etc/runlevels/sysinit
+      done
+    fi
+
     for i in acpid hwclock syslog bootmisc hostname sysctl modules connman dbus haveged issue; do
         ln -s /etc/init.d/$i /etc/runlevels/boot
     done
diff --git a/overlay/libexec/k3os/mode-disk b/overlay/libexec/k3os/mode-disk
index f15e2b26..fd295ac3 100644
--- a/overlay/libexec/k3os/mode-disk
+++ b/overlay/libexec/k3os/mode-disk
@@ -146,6 +146,22 @@ takeover()
     fi
 }
 
+### For boot from SAN, we need to ensure that the multipath devices are setup
+### while termporarily in mode=disk so that the mount & pivot_root for mode=local
+### will be the proper multipath device (rather than a single path)
+setup_multipath()
+{
+  modprobe dm-multipath
+  udevd -d
+  udevadm settle
+  udevadm trigger --type=devices --action=add
+  udevadm settle
+  multipath -v3
+  udevadm settle
+  udevadm control --exit
+}
+
+setup_multipath
 setup_mounts
 setup_k3os
 setup_kernel_squashfs