[Buildroot] [PATCH 4/5] package/petitboot: enable discovery of software RAID devices

[Reza Arbab <arbab@linux.ibm.com>]

Petitboot can support filesystems on software RAID arrays. If mdadm is
selected, install the associated udev rules to assemble the device.

Signed-off-by: Reza Arbab <arbab@linux.ibm.com>
---
 package/petitboot/63-md-raid-arrays.rules | 41 ++++++++++++++
 package/petitboot/65-md-incremental.rules | 69 +++++++++++++++++++++++
 package/petitboot/petitboot.mk            | 10 ++++
 3 files changed, 120 insertions(+)
 create mode 100644 package/petitboot/63-md-raid-arrays.rules
 create mode 100644 package/petitboot/65-md-incremental.rules

diff --git a/package/petitboot/63-md-raid-arrays.rules b/package/petitboot/63-md-raid-arrays.rules
new file mode 100644
index 000000000000..92aec36e69d4
--- /dev/null
+++ b/package/petitboot/63-md-raid-arrays.rules
@@ -0,0 +1,41 @@
+# do not edit this file, it will be overwritten on update
+
+SUBSYSTEM!="block", GOTO="md_end"
+
+# handle md arrays
+ACTION!="add|change", GOTO="md_end"
+KERNEL!="md*", GOTO="md_end"
+
+# partitions have no md/{array_state,metadata_version}, but should not
+# for that reason be ignored.
+ENV{DEVTYPE}=="partition", GOTO="md_ignore_state"
+
+# container devices have a metadata version of e.g. 'external:ddf' and
+# never leave state 'inactive'
+ATTR{md/metadata_version}=="external:[A-Za-z]*", ATTR{md/array_state}=="inactive", GOTO="md_ignore_state"
+TEST!="md/array_state", ENV{SYSTEMD_READY}="0", GOTO="md_end"
+ATTR{md/array_state}=="|clear|inactive", ENV{SYSTEMD_READY}="0", GOTO="md_end"
+LABEL="md_ignore_state"
+
+IMPORT{program}="/sbin/mdadm --detail --export $devnode"
+ENV{DEVTYPE}=="disk", ENV{MD_NAME}=="?*", SYMLINK+="disk/by-id/md-name-$env{MD_NAME}", OPTIONS+="string_escape=replace"
+ENV{DEVTYPE}=="disk", ENV{MD_UUID}=="?*", SYMLINK+="disk/by-id/md-uuid-$env{MD_UUID}"
+ENV{DEVTYPE}=="disk", ENV{MD_DEVNAME}=="?*", SYMLINK+="md/$env{MD_DEVNAME}"
+ENV{DEVTYPE}=="partition", ENV{MD_NAME}=="?*", SYMLINK+="disk/by-id/md-name-$env{MD_NAME}-part%n", OPTIONS+="string_escape=replace"
+ENV{DEVTYPE}=="partition", ENV{MD_UUID}=="?*", SYMLINK+="disk/by-id/md-uuid-$env{MD_UUID}-part%n"
+ENV{DEVTYPE}=="partition", ENV{MD_DEVNAME}=="*[^0-9]", SYMLINK+="md/$env{MD_DEVNAME}%n"
+ENV{DEVTYPE}=="partition", ENV{MD_DEVNAME}=="*[0-9]", SYMLINK+="md/$env{MD_DEVNAME}p%n"
+
+IMPORT{builtin}="blkid"
+OPTIONS+="link_priority=100"
+OPTIONS+="watch"
+ENV{ID_FS_USAGE}=="filesystem|other|crypto", ENV{ID_FS_UUID_ENC}=="?*", SYMLINK+="disk/by-uuid/$env{ID_FS_UUID_ENC}"
+ENV{ID_FS_USAGE}=="filesystem|other", ENV{ID_FS_LABEL_ENC}=="?*", SYMLINK+="disk/by-label/$env{ID_FS_LABEL_ENC}"
+
+ENV{MD_LEVEL}=="raid[1-9]*", ENV{SYSTEMD_WANTS}+="mdmonitor.service"
+
+# Tell systemd to run mdmon for our container, if we need it.
+ENV{MD_LEVEL}=="raid[1-9]*", ENV{MD_CONTAINER}=="?*", PROGRAM="/usr/bin/readlink $env{MD_CONTAINER}", ENV{MD_MON_THIS}="%c"
+ENV{MD_MON_THIS}=="?*", PROGRAM="/usr/bin/basename $env{MD_MON_THIS}", ENV{SYSTEMD_WANTS}+="mdmon@%c.service"
+
+LABEL="md_end"
diff --git a/package/petitboot/65-md-incremental.rules b/package/petitboot/65-md-incremental.rules
new file mode 100644
index 000000000000..153d12fe6f7e
--- /dev/null
+++ b/package/petitboot/65-md-incremental.rules
@@ -0,0 +1,69 @@
+# This file causes block devices with Linux RAID (mdadm) signatures to
+# automatically cause mdadm to be run.
+# See udev(8) for syntax
+
+# Don't process any events if anaconda is running as anaconda brings up
+# raid devices manually
+ENV{ANACONDA}=="?*", GOTO="md_end"
+
+# Also don't process disks that are slated to be a multipath device
+ENV{DM_MULTIPATH_DEVICE_PATH}=="?*", GOTO="md_end"
+
+# We process add events on block devices (since they are ready as soon as
+# they are added to the system), but we must process change events as well
+# on any dm devices (like LUKS partitions or LVM logical volumes) and on
+# md devices because both of these first get added, then get brought live
+# and trigger a change event.  The reason we don't process change events
+# on bare hard disks is because if you stop all arrays on a disk, then
+# run fdisk on the disk to change the partitions, when fdisk exits it
+# triggers a change event, and we want to wait until all the fdisks on
+# all member disks are done before we do anything.  Unfortunately, we have
+# no way of knowing that, so we just have to let those arrays be brought
+# up manually after fdisk has been run on all of the disks.
+
+# First, process all add events (md and dm devices will not really do
+# anything here, just regular disks, and this also won't get any imsm
+# array members either)
+SUBSYSTEM=="block", ACTION=="add|change", ENV{ID_FS_TYPE}=="linux_raid_member", \
+	RUN+="/sbin/mdadm -I --export $env{DEVNAME}"
+
+# Next, check to make sure the BIOS raid stuff wasn't turned off via cmdline
+IMPORT{cmdline}="noiswmd"
+IMPORT{cmdline}="nodmraid"
+ENV{noiswmd}=="?*", GOTO="md_imsm_inc_end"
+ENV{nodmraid}=="?*", GOTO="md_imsm_inc_end"
+SUBSYSTEM=="block", ACTION=="add", ENV{ID_FS_TYPE}=="isw_raid_member", \
+	RUN+="/sbin/mdadm -I $env{DEVNAME}"
+LABEL="md_imsm_inc_end"
+
+SUBSYSTEM=="block", ACTION=="remove", ENV{ID_PATH}=="?*", \
+	RUN+="/sbin/mdadm -If $name --path $env{ID_PATH}"
+SUBSYSTEM=="block", ACTION=="remove", ENV{ID_PATH}!="?*", \
+	RUN+="/sbin/mdadm -If $name"
+
+# Next make sure that this isn't a dm device we should skip for some reason
+ENV{DM_UDEV_RULES_VSN}!="?*", GOTO="dm_change_end"
+ENV{DM_UDEV_DISABLE_OTHER_RULES_FLAG}=="1", GOTO="dm_change_end"
+ENV{DM_SUSPENDED}=="1", GOTO="dm_change_end"
+KERNEL=="dm-*", SUBSYSTEM=="block", ENV{ID_FS_TYPE}=="linux_raid_member", \
+	ACTION=="change", RUN+="/sbin/mdadm -I $env{DEVNAME}"
+LABEL="dm_change_end"
+
+# Finally catch any nested md raid arrays.  If we brought up an md raid
+# array that's part of another md raid array, it won't be ready to be used
+# until the change event that occurs when it becomes live
+KERNEL=="md*", SUBSYSTEM=="block", ENV{ID_FS_TYPE}=="linux_raid_member", \
+	ACTION=="change", RUN+="/sbin/mdadm -I $env{DEVNAME}"
+
+# In case the initramfs only started some of the arrays in our container,
+# run incremental assembly on the container itself.  Note: we ran mdadm
+# on the container in 64-md-raid.rules, and that's how the MD_LEVEL
+# environment variable is already set.  If that disappears from the other
+# file, we will need to add this line into the middle of the next rule:
+#	IMPORT{program}="/sbin/mdadm -D --export $tempnode", \
+
+SUBSYSTEM=="block", ACTION=="add|change", KERNEL=="md*", \
+	ENV{MD_LEVEL}=="container", RUN+="/sbin/mdadm -I $env{DEVNAME}"
+
+
+LABEL="md_end"
diff --git a/package/petitboot/petitboot.mk b/package/petitboot/petitboot.mk
index 9326738aa038..596e801b781c 100644
--- a/package/petitboot/petitboot.mk
+++ b/package/petitboot/petitboot.mk
@@ -46,6 +46,16 @@ else
 PETITBOOT_CONF_OPTS += --without-fdt
 endif
 
+ifeq ($(BR2_PACKAGE_MDADM),y)
+define PETITBOOT_POST_INSTALL_MDADM
+	$(INSTALL) -D -m 0755 $(PETITBOOT_PKGDIR)/63-md-raid-arrays.rules \
+		$(TARGET_DIR)/etc/udev/rules.d/63-md-raid-arrays.rules
+	$(INSTALL) -D -m 0755 $(PETITBOOT_PKGDIR)/65-md-incremental.rules \
+		$(TARGET_DIR)/etc/udev/rules.d/65-md-incremental.rules
+endef
+PETITBOOT_POST_INSTALL_TARGET_HOOKS += PETITBOOT_POST_INSTALL_MDADM
+endif
+
 define PETITBOOT_POST_INSTALL
 	$(INSTALL) -D -m 0755 $(@D)/utils/bb-kexec-reboot \
 		$(TARGET_DIR)/usr/libexec/petitboot/bb-kexec-reboot
-- 
2.39.3

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