nixos/etc-overlay: clean up temporary directories (#339802) (0c02b307) · Commits · nix / nixpkgs

nixos/modules/system/etc/etc.nix

+18 −2

Original line number	Diff line number	Diff line
		@@ -231,13 +231,13 @@ in
		if [[ ! $IN_NIXOS_SYSTEMD_STAGE1 ]] && [[ "${config.system.build.etc}/etc" != "$(readlink -f /run/current-system/etc)" ]]; then
		echo "remounting /etc..."

		tmpMetadataMount=$(mktemp --directory)
		tmpMetadataMount=$(mktemp --directory -t nixos-etc-metadata.XXXXXXXXXX)
		mount --type erofs ${config.system.build.etcMetadataImage} $tmpMetadataMount

		# Mount the new /etc overlay to a temporary private mount.
		# This needs the indirection via a private bind mount because you
		# cannot move shared mounts.
		tmpEtcMount=$(mktemp --directory)
		tmpEtcMount=$(mktemp --directory -t nixos-etc.XXXXXXXXXX)
		mount --bind --make-private $tmpEtcMount $tmpEtcMount
		mount --type overlay overlay \
		--options lowerdir=$tmpMetadataMount::${config.system.build.etcBasedir},${etcOverlayOptions} \
		@@ -276,6 +276,22 @@ in

		# Unmount the top /etc mount to atomically reveal the new mount.
		umount --lazy --recursive /etc

		# Unmount the temporary mount
		umount --lazy "$tmpEtcMount"
		rmdir "$tmpEtcMount"

		# Unmount old metadata mounts
		# For some reason, `findmnt /tmp --submounts` does not show the nested
		# mounts. So we'll just find all mounts of type erofs and filter on the
		# name of the mountpoint.
		findmnt --type erofs --list --kernel --output TARGET \| while read -r mountPoint; do
		if [[ "$mountPoint" =~ ^/tmp/nixos-etc-metadata\..{10}$ &&
		"$mountPoint" != "$tmpMetadataMount" ]]; then
		umount --lazy $mountPoint
		rmdir "$mountPoint"
		fi
		done
		fi
		'' else ''
		# Set up the statically computed bits of /etc.

nixos/tests/activation/etc-overlay-immutable.nix

+14 −1

Original line number	Diff line number	Diff line
		@@ -27,9 +27,14 @@
		specialisation.new-generation.configuration = {
		environment.etc."newgen".text = "newgen";
		};
		specialisation.newer-generation.configuration = {
		environment.etc."newergen".text = "newergen";
		};
		};

		testScript = /* python */ ''
		newergen = machine.succeed("realpath /run/current-system/specialisation/newer-generation/bin/switch-to-configuration").rstrip()

		testScript = ''
		with subtest("/run/etc-metadata/ is mounted"):
		print(machine.succeed("mountpoint /run/etc-metadata"))

		@@ -79,5 +84,13 @@
		print(machine.succeed("ls /etc/mountpoint"))
		print(machine.succeed("stat /etc/mountpoint/extra-file"))
		print(machine.succeed("findmnt /etc/filemount"))

		machine.succeed(f"{newergen} switch")

		tmpMounts = machine.succeed("find /tmp -maxdepth 1 -type d -regex '/tmp/nixos-etc\\..*' \| wc -l").rstrip()
		metaMounts = machine.succeed("find /tmp -maxdepth 1 -type d -regex '/tmp/nixos-etc-metadata\\..*' \| wc -l").rstrip()

		assert tmpMounts == "0", f"Found {tmpMounts} remaining tmpmounts"
		assert metaMounts == "1", f"Found {metaMounts} remaining metamounts"
		'';
		}

nixos/tests/activation/etc-overlay-mutable.nix

+15 −1

Original line number	Diff line number	Diff line
		@@ -15,9 +15,14 @@
		specialisation.new-generation.configuration = {
		environment.etc."newgen".text = "newgen";
		};
		specialisation.newer-generation.configuration = {
		environment.etc."newergen".text = "newergen";
		};
		};

		testScript = /* python */ ''
		newergen = machine.succeed("realpath /run/current-system/specialisation/newer-generation/bin/switch-to-configuration").rstrip()

		testScript = ''
		with subtest("/run/etc-metadata/ is mounted"):
		print(machine.succeed("mountpoint /run/etc-metadata"))

		@@ -55,5 +60,14 @@
		print(machine.succeed("findmnt /etc/mountpoint"))
		print(machine.succeed("stat /etc/mountpoint/extra-file"))
		print(machine.succeed("findmnt /etc/filemount"))

		machine.succeed(f"{newergen} switch")
		assert machine.succeed("cat /etc/newergen") == "newergen"

		tmpMounts = machine.succeed("find /tmp -maxdepth 1 -type d -regex '/tmp/nixos-etc\\..*' \| wc -l").rstrip()
		metaMounts = machine.succeed("find /tmp -maxdepth 1 -type d -regex '/tmp/nixos-etc-metadata\\..*' \| wc -l").rstrip()

		assert tmpMounts == "0", f"Found {tmpMounts} remaining tmpmounts"
		assert metaMounts == "1", f"Found {metaMounts} remaining metamounts"
		'';
		}