Merge feature-mkfs.ext4 into main

5 files changed, 51 insertions, 26 deletions

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 188d919..24cbab1 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -28,14 +28,14 @@ release_test:
   script:
     - apt-get update
     - apt-get dist-upgrade --yes
-    - apt-get --no-install-recommends --yes install curl e2fsprogs genext2fs mmdebstrap openssh-client qemu-kvm dpkg-dev
+    - apt-get --no-install-recommends --yes install curl e2fsprogs mmdebstrap openssh-client qemu-kvm dpkg-dev
     - PATH=$(pwd)/bin:$PATH ./tests/create-and-run.sh $(dpkg --print-architecture) "$RELEASE"
 
 debci_test:
   script:
     - apt-get update
     - apt-get dist-upgrade --yes
-    - apt-get --no-install-recommends --yes install e2fsprogs genext2fs mmdebstrap openssh-client qemu-kvm dpkg-dev
+    - apt-get --no-install-recommends --yes install e2fsprogs mmdebstrap openssh-client qemu-kvm dpkg-dev
     - PATH=$(pwd)/bin:$PATH ./tests/create-and-run.sh $(dpkg --print-architecture) ""
 
 arch_test:
@@ -54,6 +54,6 @@ arch_test:
     - test -e /proc/sys/fs/binfmt_misc/status || mount -t binfmt_misc binfmt_misc /proc/sys/fs/binfmt_misc
     - apt-get update
     - apt-get dist-upgrade --yes
-    - apt-get --no-install-recommends --yes install curl e2fsprogs genext2fs mmdebstrap openssh-client qemu-system arch-test qemu-user-static file systemd dpkg-dev debian-ports-archive-keyring
+    - apt-get --no-install-recommends --yes install curl e2fsprogs mmdebstrap openssh-client qemu-system arch-test qemu-user-static file systemd dpkg-dev debian-ports-archive-keyring
     - /lib/systemd/systemd-binfmt
     - PATH=$(pwd)/bin:$PATH ./tests/create-and-run.sh "$ARCHITECTURE" sid
diff --git a/README.md b/README.md
index 1ccda36..f757993 100644
--- a/README.md
+++ b/README.md
@@ -32,10 +32,10 @@ A regular user account[^1] suffices. The following Debian packages should be
 installed:
  * `arch-test` (when running foreign images)
  * `e2fsprogs`
- * `genext2fs` (used by `mmdebstrap`)
  * `mmdebstrap`
  * `qemu-system-something`
  * `qemu-user-static` (when creating foreign images)
+ * `uidmap` (for using user namespaces)
 
 What is this image format precisely?
 ====================================
@@ -63,8 +63,7 @@ The other aspect is restricting to Debian-based systems. This allows for a lot
 of simplification of the problem space.
 
 While most similar tools require root privileges at some point, this one works
-with either fakeroot or a subuid allocation for user namespaces, which is often
-available.
+with a subuid allocation for user namespaces, which is often available.
 
 The implementation is so short that it still is feasible to read and understand
 it. Let's see how long that lasts.
diff --git a/bin/debvm-create b/bin/debvm-create
index bfc02e3..1c59a83 100755
--- a/bin/debvm-create
+++ b/bin/debvm-create
@@ -74,8 +74,8 @@ This is specific to using B<finit>, B<runit>, B<systemd> or B<sysv> as init syst
 
 =item B<ext4>
 
-Internally, B<mmdebstrap> creates a tar archive first and converts that to ext2, which is then upgraded to ext4.
-This option causes the conversion to ext2 and further steps to be skipped and the output image will be a tar archive instead.
+Normally, B<mmdebstrap> bootstraps to a temporary directory and we create the output ext4 image from that directory.
+This option causes the creation of the ext4 image to be skipped and the output file becomes a tar archive of the temporary directory instead.
 Such a tar archive is not suitable for being booted by B<debvm-run>.
 
 =item B<ifupdown>
@@ -116,7 +116,7 @@ Without the hook, dependencies will pull the B<usrmerge> package as needed, whic
 =item B<-z> I<size>, B<--size>=I<size>
 
 Specify the minimum image size as an integer and optional unit (example: 10K is 10*1024).
-Units are K,M,G,T,P,E,Z,Y (powers of 1024) or KB,MB,... (powers of 1000).
+Units are K,M,G,T (powers of 1024).
 The resulting image will be grown as a sparse file to this size if necessary.
 The default is 1 GB.
 
@@ -294,7 +294,7 @@ if ! check_skip kernel; then
 	set -- "--customize-hook=$SHARE_DIR/customize-kernel.sh" "$@"
 fi
 
-MMFORMAT=ext2
+MMFORMAT=directory
 # output a tarball if the ext4 step is skipped
 if check_skip ext4; then
 	MMFORMAT=tar
@@ -305,9 +305,16 @@ set -- \
 	--verbose \
 	--variant=apt \
 	"--format=$MMFORMAT" \
+	--skip=output/dev \
 	'--customize-hook=echo "LABEL=debvm / ext4 defaults 0 0" >"$1/etc/fstab"' \
 	"$@"
 
+if test "$(id -u)" = 0; then
+	set -- --mode=root "$@"
+else
+	set -- --mode=unshare "$@"
+fi
+
 if test -n "$ARCHITECTURE"; then
 	set -- "--architecture=$ARCHITECTURE" "$@"
 fi
@@ -393,20 +400,41 @@ if ! check_skip autologin; then
 	set -- "--customize-hook=$SHARE_DIR/customize-autologin.sh" "$@"
 fi
 
-set -- "$SUITE" "$IMAGE" "$@"
+if test "$(id -u)" = 0; then
+	run_inside_userns() {
+		"$@"
+	}
+else
+	run_inside_userns() {
+		unshare --user --map-auto --map-user=65536 --map-group=65536 --keep-caps -- "$@"
+	}
+fi
 
-set -ex
+if check_skip ext4; then
+	set -- "$SUITE" "$IMAGE" "$@"
+	set -x
+	exec mmdebstrap "$@"
+fi
 
-mmdebstrap "$@"
+TEMPROOT=
+cleanup() {
+	if test -n "$TEMPROOT"; then
+		run_inside_userns rm -Rf "$TEMPROOT"
+	fi
+}
 
-{ set +x; } 2>/dev/null
-check_skip ext4 && exit
+trap cleanup EXIT
+# The default action for these signals does not invoke the EXIT trap.
+trap 'exit 1' HUP INT QUIT TERM
+TEMPROOT="$(mktemp -d)"
 
-set -x
+set -- "$SUITE" "$TEMPROOT" "$@"
+
+set -ex
+
+# Create and truncate the file with "normal" permission.
+: >"$IMAGE"
+
+mmdebstrap "$@"
 
-truncate -s ">$SIZE" "$IMAGE"
-/sbin/resize2fs "$IMAGE"
-/sbin/tune2fs -L debvm -c 0 -i 0 -O dir_index,dir_nlink,extents,extra_isize,flex_bg,has_journal,huge_file "$IMAGE"
-/sbin/resize2fs -b "$IMAGE"
-# Must fsck after tune2fs: https://ext4.wiki.kernel.org/index.php/UpgradeToExt4
-/sbin/fsck.ext4 -fDp "$IMAGE"
+run_inside_userns /sbin/mkfs.ext4 -L debvm -d "$TEMPROOT" "$IMAGE" "$SIZE"
diff --git a/debian/control b/debian/control
index d4dbda0..341e8a7 100644
--- a/debian/control
+++ b/debian/control
@@ -15,7 +15,6 @@ Depends:
  ${misc:Depends},
  dpkg-dev,
  e2fsprogs,
- genext2fs,
  mmdebstrap (>= 1.3.0),
  passwd,
  qemu-kvm (>> 1:8.0) | qemu-system-any,
@@ -29,8 +28,7 @@ Recommends:
  qemu-system,
  qemu-user-static,
  seabios,
- uidmap | fakeroot,
- uidmap | fakechroot,
+ uidmap,
 Suggests:
  qemu-system-gui,
 Description: create and run virtual machines for various Debian releases and architectures
diff --git a/tests/dist-upgrades.sh b/tests/dist-upgrades.sh
index 121f87e..171500a 100755
--- a/tests/dist-upgrades.sh
+++ b/tests/dist-upgrades.sh
@@ -2,7 +2,7 @@
 # Copyright 2022 Jochen Sprickerhof <debvm@jochen.sprickerhof.de>
 # SPDX-License-Identifier: MIT
 #
-# apt install e2fsprogs genext2fs mmdebstrap openssh-client qemu-kvm
+# apt install e2fsprogs mmdebstrap openssh-client qemu-kvm
 
 set -x