From: Benjamin Drung <benjamin.drung@canonical.com>
Date: Wed, 4 Feb 2026 12:57:19 +0000 (+0100)
Subject: feat: merge rd.overlayfs into rd.overlay
X-Git-Tag: 110~44
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d90c59bb28e80a8a3d6e14ecf499aeba00896a15;p=thirdparty%2Fdracut-ng.git

feat: merge rd.overlayfs into rd.overlay

Having both `rd.overlayfs` and `rd.overlay` is confusing.

Standardize on using `rd.overlay` for the overlayfs Dracut module. Merge
`rd.overlayfs` into `rd.overlay`. `rd.overlay` can be a boolean or point
to a storage device now.

Commit b77ae7eb8523 ("feat: rename rd.live.overlay.overlayfs to
rd.overlayfs") introduced `rd.overlayfs` after the release 109. So no
Dracut release included `rd.overlayfs` and therefore no backward
compatility for `rd.overlayfs` is needed.
---

diff --git a/man/dracut.cmdline.7.adoc b/man/dracut.cmdline.7.adoc
index eff195fc7..789348618 100644
--- a/man/dracut.cmdline.7.adoc
+++ b/man/dracut.cmdline.7.adoc
@@ -1090,7 +1090,7 @@ OverlayFS
 ~~~~~~~~~
 Requires the dracut 'overlayfs' module.
 
-**rd.overlayfs=**1::
+**rd.overlay**::
 Enables the use of the *OverlayFS* kernel module, if available, to provide a
 copy-on-write union directory for the root filesystem.  OverlayFS overlays are
 directories of the files that have changed on the read-only base (lower)
@@ -1177,7 +1177,7 @@ filesystem, which often provide only a small number of gigabytes of free space.
 This shortage could be remedied by building the root filesystem with more
 allocated free space, or the OverlayFS based overlay mount method can be used.
 
-When the _rd.overlayfs_ option is specified or when
+When the _rd.overlay_ option is specified or when
 _rd.overlay=_ points to an appropriate directory with a sister at
 `/../ovlwork`, then an OverlayFS based overlay mount is employed.  Such a
 persistent OverlayFS overlay can extend the available root filesystem storage
@@ -1354,7 +1354,7 @@ where _<label>_ and _<uuid>_ are the LABEL and UUID of the filesystem specified
 by the **root=**live:__<path|url>__ device.
 
 If a persistent overlay __is detected__ at the standard LiveOS path,
-and _rd.overlayfs_ is not set to 1, the overlay type (either
+and _rd.overlay_ is not set to 1, the overlay type (either
 Device-mapper or OverlayFS) will be detected and it will be used.
 --
 +
@@ -1547,7 +1547,7 @@ UNICODE:: vconsole.unicode (since version 008)
 
 EXT_KEYMAP:: vconsole.keymap.ext (since version 008)
 
-rd.live.overlay.overlayfs:: rd.overlayfs (since version 110)
+rd.live.overlay.overlayfs:: rd.overlay (since version 110)
 
 rd.live.overlay.readonly:: rd.overlay.readonly (since version 110)
 
diff --git a/modules.d/70dmsquash-live-autooverlay/create-overlay.sh b/modules.d/70dmsquash-live-autooverlay/create-overlay.sh
index 01a576066..0eb8948ff 100755
--- a/modules.d/70dmsquash-live-autooverlay/create-overlay.sh
+++ b/modules.d/70dmsquash-live-autooverlay/create-overlay.sh
@@ -1,6 +1,7 @@
 #!/bin/sh
 
 command -v getarg > /dev/null || . /lib/dracut-lib.sh
+command -v get_rd_overlay > /dev/null || . /lib/overlayfs-lib.sh
 
 if getargbool 0 rd.live.debug; then
     exec > /tmp/create-overlay.$$.out
@@ -9,7 +10,7 @@ if getargbool 0 rd.live.debug; then
 fi
 
 gatherData() {
-    overlay=$(getarg rd.overlay -d rd.live.overlay)
+    overlay=$(get_rd_overlay)
     if [ -z "$overlay" ]; then
         info "Skipping overlay creation: kernel command line parameter 'rd.overlay' is not set"
         exit 0
diff --git a/modules.d/70dmsquash-live/dmsquash-generator.sh b/modules.d/70dmsquash-live/dmsquash-generator.sh
index ef6b072b7..00553ae63 100755
--- a/modules.d/70dmsquash-live/dmsquash-generator.sh
+++ b/modules.d/70dmsquash-live/dmsquash-generator.sh
@@ -46,7 +46,7 @@ GENERATOR_DIR="$2"
 [ -d "$GENERATOR_DIR" ] || mkdir -p "$GENERATOR_DIR"
 
 getargbool 0 rd.overlay.readonly -d rd.live.overlayfs.readonly && readonly_overlay="--readonly" || readonly_overlay=""
-getargbool 0 rd.overlayfs -d rd.live.overlay.overlayfs && overlayfs="yes"
+getargbool 0 rd.overlay -d rd.live.overlay.overlayfs && overlayfs="yes"
 [ -e /xor_overlayfs ] && xor_overlayfs="yes"
 [ -e /xor_readonly ] && xor_readonly="--readonly"
 ROOTFLAGS="$(getarg rootflags)"
diff --git a/modules.d/70dmsquash-live/dmsquash-live-root.sh b/modules.d/70dmsquash-live/dmsquash-live-root.sh
index 9829f0a99..7730ffe23 100755
--- a/modules.d/70dmsquash-live/dmsquash-live-root.sh
+++ b/modules.d/70dmsquash-live/dmsquash-live-root.sh
@@ -3,6 +3,7 @@
 command -v getarg > /dev/null || . /lib/dracut-lib.sh
 command -v det_fs > /dev/null || . /lib/fs-lib.sh
 command -v unpack_archive > /dev/null || . /lib/img-lib.sh
+command -v get_rd_overlay > /dev/null || . /lib/overlayfs-lib.sh
 
 PATH=/usr/sbin:/usr/bin:/sbin:/bin
 
@@ -26,13 +27,13 @@ getargbool 0 rd.live.ram && live_ram="yes"
 getargbool 0 rd.overlay.reset -d rd.live.overlay.reset && reset_overlay="yes"
 getargbool 0 rd.overlay.readonly -d rd.live.overlay.readonly && readonly_overlay="--readonly" || readonly_overlay=""
 getargbool 0 rd.live.overlay.nouserconfirmprompt && overlay_no_user_confirm_prompt="--noprompt" || overlay_no_user_confirm_prompt=""
-overlay=$(getarg rd.overlay -d rd.live.overlay)
+overlay=$(get_rd_overlay)
 getargbool 0 rd.writable.fsimg && writable_fsimg="yes"
 overlay_size=$(getarg rd.live.overlay.size=)
 [ -z "$overlay_size" ] && overlay_size=32768
 
 getargbool 0 rd.live.overlay.thin && thin_snapshot="yes"
-getargbool 0 rd.overlayfs -d rd.live.overlay.overlayfs && overlayfs="yes"
+getargbool 0 rd.overlay -d rd.live.overlay.overlayfs && overlayfs="yes"
 
 # Take a path to a disk label and return the parent disk if it is a partition
 # Otherwise returns the original path
@@ -415,8 +416,8 @@ fi
 
 ROOTFLAGS="$(getarg rootflags)"
 
-if [ "$overlayfs" = required ]; then
-    echo "rd.overlayfs=1" > /etc/cmdline.d/20-dmsquash-need-overlay.conf
+if [ "$overlayfs" = required ] && ! getargbool 0 rd.overlay; then
+    echo "rd.overlay" > /etc/cmdline.d/20-dmsquash-need-overlay.conf
 fi
 
 if [ -n "$overlayfs" ]; then
diff --git a/modules.d/70livenet/livenet-generator.sh b/modules.d/70livenet/livenet-generator.sh
index 3980bf811..f9434efa6 100755
--- a/modules.d/70livenet/livenet-generator.sh
+++ b/modules.d/70livenet/livenet-generator.sh
@@ -50,7 +50,7 @@ GENERATOR_DIR="$2"
 [ -d "$GENERATOR_DIR" ] || mkdir -p "$GENERATOR_DIR"
 
 getargbool 0 rd.overlay.readonly -d rd.live.overlay.readonly && readonly_overlay="--readonly" || readonly_overlay=""
-getargbool 0 rd.overlayfs -d rd.live.overlay.overlayfs && overlayfs="yes"
+getargbool 0 rd.overlay -d rd.live.overlay.overlayfs && overlayfs="yes"
 [ -e /xor_overlayfs ] && xor_overlayfs="yes"
 [ -e /xor_readonly ] && xor_readonly="--readonly"
 ROOTFLAGS="$(getarg rootflags)"
diff --git a/modules.d/70overlayfs/module-setup.sh b/modules.d/70overlayfs/module-setup.sh
index 50e35aa5c..729a845d1 100755
--- a/modules.d/70overlayfs/module-setup.sh
+++ b/modules.d/70overlayfs/module-setup.sh
@@ -18,4 +18,5 @@ install() {
     inst_hook mount 01 "$moddir/mount-overlayfs.sh"       # overlay on top of block device
     inst_hook pre-pivot 00 "$moddir/prepare-overlayfs.sh" # prepare for network root (e.g. nfs)
     inst_hook pre-pivot 10 "$moddir/mount-overlayfs.sh"   # overlay on top of network device
+    inst_simple "$moddir/overlayfs-lib.sh" "/lib/overlayfs-lib.sh"
 }
diff --git a/modules.d/70overlayfs/mount-overlayfs.sh b/modules.d/70overlayfs/mount-overlayfs.sh
index 379d03f64..8514211ea 100755
--- a/modules.d/70overlayfs/mount-overlayfs.sh
+++ b/modules.d/70overlayfs/mount-overlayfs.sh
@@ -1,10 +1,11 @@
 #!/bin/sh
 
 command -v getarg > /dev/null || . /lib/dracut-lib.sh
+command -v get_rd_overlay > /dev/null || . /lib/overlayfs-lib.sh
 
-getargbool 0 rd.overlayfs -d rd.live.overlay.overlayfs && overlayfs="yes"
+getargbool 0 rd.overlay -d rd.live.overlay.overlayfs && overlayfs="yes"
 getargbool 0 rd.overlay.readonly -d rd.live.overlayfs.readonly && readonly_overlay="--readonly" || readonly_overlay=""
-overlay=$(getarg rd.overlay -d rd.live.overlay)
+overlay=$(get_rd_overlay)
 
 [ -n "$overlayfs" ] || [ -n "$overlay" ] || return 0
 
diff --git a/modules.d/70overlayfs/overlayfs-lib.sh b/modules.d/70overlayfs/overlayfs-lib.sh
new file mode 100644
index 000000000..182a886e0
--- /dev/null
+++ b/modules.d/70overlayfs/overlayfs-lib.sh
@@ -0,0 +1,17 @@
+#!/bin/sh
+
+command -v getarg > /dev/null || . /lib/dracut-lib.sh
+
+# Fetch non-boolean value for rd.overlay or fall back to rd.live.overlay
+get_rd_overlay() {
+    local overlay
+
+    overlay=$(getarg rd.overlay)
+    case $overlay in
+        0 | no | off | "" | 1)
+            overlay=$(getarg rd.live.overlay) || return 1
+            warn "Kernel command line option 'rd.live.overlay' is deprecated, use 'rd.overlay' instead."
+            ;;
+    esac
+    echo "$overlay"
+}
diff --git a/modules.d/70overlayfs/prepare-overlayfs.sh b/modules.d/70overlayfs/prepare-overlayfs.sh
index c9439ea00..6aeb9b4ec 100755
--- a/modules.d/70overlayfs/prepare-overlayfs.sh
+++ b/modules.d/70overlayfs/prepare-overlayfs.sh
@@ -1,12 +1,12 @@
 #!/bin/sh
 
 command -v getarg > /dev/null || . /lib/dracut-lib.sh
+command -v get_rd_overlay > /dev/null || . /lib/overlayfs-lib.sh
 
-getargbool 0 rd.overlayfs -d rd.live.overlay.overlayfs && overlayfs="yes"
-getargbool 0 rd.overlay.reset -d rd.live.overlay.reset && reset_overlay="yes"
-overlay=$(getarg rd.overlay -d rd.live.overlay)
+getargbool 0 rd.overlay -d rd.live.overlay.overlayfs || return 0
 
-[ -n "$overlayfs" ] || [ -n "$overlay" ] || return 0
+getargbool 0 rd.overlay.reset -d rd.live.overlay.reset && reset_overlay="yes"
+overlay=$(get_rd_overlay)
 
 overlay_mode="tmpfs"
 overlay_device=""
diff --git a/test/TEST-21-OVERLAYFS/assertion.sh b/test/TEST-21-OVERLAYFS/assertion.sh
index a74f6e4fc..28c47f894 100755
--- a/test/TEST-21-OVERLAYFS/assertion.sh
+++ b/test/TEST-21-OVERLAYFS/assertion.sh
@@ -2,12 +2,18 @@
 
 # required binaries: cat grep
 
-if ! grep -q " overlay " /proc/mounts; then
-    echo "overlay filesystem not found in /proc/mounts" >> /run/failed
-fi
+if grep -q 'test.expect=none' /proc/cmdline; then
+    if grep -q " overlay " /proc/mounts; then
+        echo "overlay filesystem found in /proc/mounts" >> /run/failed
+    fi
+else
+    if ! grep -q " overlay " /proc/mounts; then
+        echo "overlay filesystem not found in /proc/mounts" >> /run/failed
+    fi
 
-if ! echo > /test-overlay-write; then
-    echo "overlay is not writable" >> /run/failed
+    if ! echo > /test-overlay-write; then
+        echo "overlay is not writable" >> /run/failed
+    fi
 fi
 
 if grep -q 'test.expect=device' /proc/cmdline; then
diff --git a/test/TEST-21-OVERLAYFS/test.sh b/test/TEST-21-OVERLAYFS/test.sh
index 47698358d..e34b8d991 100755
--- a/test/TEST-21-OVERLAYFS/test.sh
+++ b/test/TEST-21-OVERLAYFS/test.sh
@@ -30,7 +30,9 @@ test_run() {
     local overlay_uuid
     overlay_uuid=$(blkid -s UUID -o value "$TESTDIR"/overlay.img)
 
-    client_run "tmpfs overlay" "rd.overlayfs=1 test.expect=tmpfs"
+    client_run "overlay disabled (rd.overlay=0)" "rd.overlay=0 test.expect=none"
+    client_run "tmpfs overlay (rd.overlay)" "rd.overlay test.expect=tmpfs"
+    client_run "tmpfs overlay (rd.overlay=1)" "rd.overlay=1 test.expect=tmpfs"
     client_run "persistent device overlay (LABEL)" "rd.overlay=LABEL=OVERLAY test.expect=device"
     client_run "persistent device overlay (UUID)" "rd.overlay=UUID=$overlay_uuid test.expect=device"
     client_run "persistent device overlay (device path)" \
diff --git a/test/TEST-30-DMSQUASH/test.sh b/test/TEST-30-DMSQUASH/test.sh
index 5da1d8238..10c988593 100755
--- a/test/TEST-30-DMSQUASH/test.sh
+++ b/test/TEST-30-DMSQUASH/test.sh
@@ -30,7 +30,7 @@ client_run() {
 
     "$testdir"/run-qemu \
         "${disk_args[@]}" \
-        -append "$TEST_KERNEL_CMDLINE rd.overlayfs=1 root=live:/dev/disk/by-label/dracut $client_opts" \
+        -append "$TEST_KERNEL_CMDLINE rd.overlay root=live:/dev/disk/by-label/dracut $client_opts" \
         -initrd "$TESTDIR"/initramfs.testing
     check_qemu_log
 
diff --git a/test/TEST-60-NFS/test.sh b/test/TEST-60-NFS/test.sh
index 198c7a720..0638fdcc4 100755
--- a/test/TEST-60-NFS/test.sh
+++ b/test/TEST-60-NFS/test.sh
@@ -187,10 +187,10 @@ test_nfsv4() {
         "root=dhcp" 192.168.50.3 wsize=4096
 
     client_test "NFSv4 Overlayfs root=nfs4:..." 52:54:00:12:34:84 \
-        "root=nfs4:192.168.50.1:/client rd.overlayfs=1 " 192.168.50.1 -wsize=4096
+        "root=nfs4:192.168.50.1:/client rd.overlay " 192.168.50.1 -wsize=4096
 
     client_test "NFSv4 Live Overlayfs root=nfs4:..." 52:54:00:12:34:84 \
-        "root=nfs4:192.168.50.1:/client rd.live.image rd.overlayfs=1" 192.168.50.1 -wsize=4096
+        "root=nfs4:192.168.50.1:/client rd.live.image rd.overlay" 192.168.50.1 -wsize=4096
 
     return 0
 }