sys-apps/ignition: Fix giving partition number 0 to get next available

changelog/bugfixes/2026-06-08-ignition-part-0.md

@@ -0,0 +1 @@
+- Fixed using Ignition to create new partitions with number 0 to get the next available slot. ([ignition#2234](https://github.com/coreos/ignition/pull/2234))

sdk_container/src/third_party/coreos-overlay/sys-apps/ignition/files/0019-stages-disks-Fix-handling-of-device-mapper-when-part.patch

@@ -0,0 +1,136 @@
+From 1a2908e042ce2fb35cf87890b0cceb25be399383 Mon Sep 17 00:00:00 2001
+From: James Le Cuirot <jlecuirot@microsoft.com>
+Date: Thu, 11 Jun 2026 23:03:00 +0100
+Subject: [PATCH 19/21] stages/disks: Fix handling of device mapper when
+ partitioning
+
+It was handled correctly when checking whether the whole disk was in use
+but not when checking individual partitions.
+
+Signed-off-by: James Le Cuirot <jlecuirot@microsoft.com>
+--- a/internal/exec/stages/disks/partitions.go
++++ b/internal/exec/stages/disks/partitions.go
+@@ -323,11 +323,15 @@ func (p PartitionList) Swap(i, j int) {
+ 	p[i], p[j] = p[j], p[i]
+ }
+
+-func isBlockDevMapper(blockDevResolved string) bool {
++// blockDevDMName returns the device mapper name for the given block device,
++// or an empty string if it is not a device mapper device.
++func blockDevDMName(blockDevResolved string) string {
+ 	blockDevNode := filepath.Base(blockDevResolved)
+-	dmName := fmt.Sprintf("/sys/class/block/%s/dm/name", blockDevNode)
+-	_, err := os.Stat(dmName)
+-	return err == nil
++	dmNameBytes, err := os.ReadFile(fmt.Sprintf("/sys/class/block/%s/dm/name", blockDevNode))
++	if err != nil {
++		return ""
++	}
++	return strings.TrimSpace(string(dmNameBytes))
+ }
+
+ // Expects a /dev/xyz path
+@@ -368,8 +372,23 @@ func blockDevMounted(blockDevResolved string) (bool, error) {
+ }
+
+ // Expects a /dev/xyz path
+-func blockDevPartitions(blockDevResolved string) ([]string, error) {
+-	_, blockDevNode := filepath.Split(blockDevResolved)
++func blockDevPartitions(blockDevResolved string, dmName string) ([]string, error) {
++	blockDevNode := filepath.Base(blockDevResolved)
++
++	if dmName != "" {
++		// For device mapper (e.g. multipath), partition devices are
++		// separate DM nodes. Find them via dm-name symlinks.
++		matches, _ := filepath.Glob(fmt.Sprintf("/dev/disk/by-id/dm-name-%sp[0-9]*", dmName))
++		var partitions []string
++		for _, m := range matches {
++			resolved, err := filepath.EvalSymlinks(m)
++			if err != nil {
++				return nil, fmt.Errorf("failed to resolve %q: %v", m, err)
++			}
++			partitions = append(partitions, resolved)
++		}
++		return partitions, nil
++	}
+
+ 	// This also works for extended MBR partitions
+ 	sysDir := fmt.Sprintf("/sys/class/block/%s/", blockDevNode)
+@@ -388,12 +407,11 @@ func blockDevPartitions(blockDevResolved string) ([]string, error) {
+ }
+
+ // Expects a /dev/xyz path
+-func blockDevInUse(blockDevResolved string, skipPartitionCheck bool) (bool, []string, error) {
++func blockDevInUse(blockDevResolved string, dmName string, skipPartitionCheck bool) (bool, []string, error) {
+ 	// Note: This ignores swap and LVM usage
+ 	inUse := false
+-	isDevMapper := isBlockDevMapper(blockDevResolved)
+ 	held := false
+-	if !isDevMapper {
++	if dmName == "" {
+ 		var err error
+ 		held, err = blockDevHeld(blockDevResolved)
+ 		if err != nil {
+@@ -408,13 +426,13 @@ func blockDevInUse(blockDevResolved string, skipPartitionCheck bool) (bool, []st
+ 	if skipPartitionCheck {
+ 		return inUse, nil, nil
+ 	}
+-	partitions, err := blockDevPartitions(blockDevResolved)
++	partitions, err := blockDevPartitions(blockDevResolved, dmName)
+ 	if err != nil {
+ 		return false, nil, fmt.Errorf("failed to retrieve partitions of %q: %v", blockDevResolved, err)
+ 	}
+ 	var activePartitions []string
+ 	for _, partition := range partitions {
+-		partInUse, _, err := blockDevInUse(partition, true)
++		partInUse, _, err := blockDevInUse(partition, dmName, true)
+ 		if err != nil {
+ 			return false, nil, fmt.Errorf("failed to check if partition %q is in use: %v", partition, err)
+ 		}
+@@ -435,6 +453,18 @@ func partitionNumberPrefix(blockDevResolved string) string {
+ 	return ""
+ }
+
++// partitionDevPath returns the expected device path for the given partition
++// number on the given disk. For device mapper devices (e.g. multipath), the
++// partition devices are separate DM nodes, so we locate them via
++// /dev/disk/by-id/dm-name-<name>p<N> symlinks. The returned path may or may
++// not exist on disk.
++func partitionDevPath(blockDevResolved string, dmName string, prefix string, partNum int) string {
++	if dmName == "" {
++		return fmt.Sprintf("%s%s%d", blockDevResolved, prefix, partNum)
++	}
++	return fmt.Sprintf("/dev/disk/by-id/dm-name-%sp%d", dmName, partNum)
++}
++
+ // partitionDisk partitions devAlias according to the spec given by dev
+ func (s stage) partitionDisk(dev types.Disk, devAlias string) error {
+ 	blockDevResolved, err := filepath.EvalSymlinks(devAlias)
+@@ -442,7 +472,9 @@ func (s stage) partitionDisk(dev types.Disk, devAlias string) error {
+ 		return fmt.Errorf("failed to resolve %q: %v", devAlias, err)
+ 	}
+
+-	inUse, activeParts, err := blockDevInUse(blockDevResolved, false)
++	dmName := blockDevDMName(blockDevResolved)
++
++	inUse, activeParts, err := blockDevInUse(blockDevResolved, dmName, false)
+ 	if err != nil {
+ 		return fmt.Errorf("failed usage check on %q: %v", devAlias, err)
+ 	}
+@@ -499,7 +531,12 @@ func (s stage) partitionDisk(dev types.Disk, devAlias string) error {
+ 		}
+ 		matches := exists && matchErr == nil
+ 		wipeEntry := cutil.IsTrue(part.WipePartitionEntry)
+-		partInUse := iutil.StrSliceContains(activeParts, fmt.Sprintf("%s%s%d", blockDevResolved, prefix, part.Number))
++
++		partDevForCheck := partitionDevPath(blockDevResolved, dmName, prefix, part.Number)
++		if resolved, err := filepath.EvalSymlinks(partDevForCheck); err == nil {
++			partDevForCheck = resolved
++		}
++		partInUse := iutil.StrSliceContains(activeParts, partDevForCheck)
+
+ 		var modification bool
+
+-- 
+2.54.0
+