On 11/30/25 23:45, Alyssa Ross wrote:
This will solve the problem of mounts for VMs being very annoying to clean up, as evidenced in run-appimage. It was looking to be even worse for Flatpak.
Does the updater also need to be adjusted?
Signed-off-by: Alyssa Ross <hi@alyssa.is> --- .../template/data/service/dbus/run | 2 ++ .../template/data/service/vhost-user-fs/run | 4 +-- .../image/usr/bin/create-vm-dependencies | 23 ++++++++++++++--- host/rootfs/image/usr/bin/run-appimage | 25 +++++++++---------- 4 files changed, 34 insertions(+), 20 deletions(-)
diff --git a/host/rootfs/image/etc/s6-linux-init/run-image/service/vm-services/template/data/service/dbus/run b/host/rootfs/image/etc/s6-linux-init/run-image/service/vm-services/template/data/service/dbus/run index 351fc68..9b23192 100755 --- a/host/rootfs/image/etc/s6-linux-init/run-image/service/vm-services/template/data/service/dbus/run +++ b/host/rootfs/image/etc/s6-linux-init/run-image/service/vm-services/template/data/service/dbus/run @@ -4,6 +4,8 @@
importas -i VM VM
+nsenter --mount=${VM}/mount + dbus-daemon --config-file /usr/share/dbus-1/session.conf --print-address 3 diff --git a/host/rootfs/image/etc/s6-linux-init/run-image/service/vm-services/template/data/service/vhost-user-fs/run b/host/rootfs/image/etc/s6-linux-init/run-image/service/vm-services/template/data/service/vhost-user-fs/run index 5d5ad7d..3848b0c 100755 --- a/host/rootfs/image/etc/s6-linux-init/run-image/service/vm-services/template/data/service/vhost-user-fs/run +++ b/host/rootfs/image/etc/s6-linux-init/run-image/service/vm-services/template/data/service/vhost-user-fs/run @@ -12,8 +12,6 @@ export TMPDIR /run
# The VM should not be able to write directly into a tmpfs, but there # can be writable block-based bind mounted subdirectories.
Comment should be moved to the code that does the bind mount. Also, this comment is somewhat stale: the main reason to prevent writing into the toplevel fs/ folder is that host tools (like the updater) assume symlinks can't be created in it.
-unshare -m --propagation slave importas -i VM VM -if { mount --rbind -o ro ${VM}/fs ${VM}/fs } - +nsenter --mount=${VM}/mount virtiofsd --fd 3 --shared-dir ${VM}/fs diff --git a/host/rootfs/image/usr/bin/create-vm-dependencies b/host/rootfs/image/usr/bin/create-vm-dependencies index f3a1b69..21681cd 100755 --- a/host/rootfs/image/usr/bin/create-vm-dependencies +++ b/host/rootfs/image/usr/bin/create-vm-dependencies @@ -1,11 +1,26 @@ #!/bin/execlineb -S1 # SPDX-License-Identifier: EUPL-1.2+ -# SPDX-FileCopyrightText: 2024 Alyssa Ross <hi@alyssa.is> +# SPDX-FileCopyrightText: 2024-2025 Alyssa Ross <hi@alyssa.is>
-if { mount -m --rbind -o nofail /run/vm/by-id/${1}/config/fs /run/vm/by-id/${1}/fs/config } +if { touch /run/vm/by-id/${1}/mount } +if { mount --make-private --bind /run/vm/by-id/${1}/mount /run/vm/by-id/${1}/mount }
-if { mkdir -p /run/vm/by-id/${1}/doc-run/doc /run/vm/by-id/${1}/fs/doc } -if { mount --rbind /run/vm/by-id/${1}/doc-run/doc /run/vm/by-id/${1}/fs/doc } +if { + unshare --mount=/run/vm/by-id/${1}/mount + + if { + mkdir -p + /run/vm/by-id/${1}/doc-run/doc + /run/vm/by-id/${1}/fs/config + /run/vm/by-id/${1}/fs/doc I would also create /run/vm/by-id/${1}/config/fs...
+ } + + if { mount --make-shared --rbind /run/vm/by-id/${1} /run/vm/by-id/${1} } + + if { mount --rbind -o ro /run/vm/by-id/${1}/fs /run/vm/by-id/${1}/fs }
VMs should not be able to write to their own config, so this and the next like should be swapped.
+ if { mount --rbind -o nofail /run/vm/by-id/${1}/config/fs /run/vm/by-id/${1}/fs/config }
...and remove this `-o nofail`.
+ mount --rbind /run/vm/by-id/${1}/doc-run/doc /run/vm/by-id/${1}/fs/doc +}
if { s6-instance-create /run/service/vm-services $1 } elglob -0 services /run/service/vm-services/instance/${1}/services/* diff --git a/host/rootfs/image/usr/bin/run-appimage b/host/rootfs/image/usr/bin/run-appimage index 6ccc61f..f2fe7bc 100755 --- a/host/rootfs/image/usr/bin/run-appimage +++ b/host/rootfs/image/usr/bin/run-appimage @@ -1,14 +1,12 @@ #!/bin/execlineb -S1 # SPDX-License-Identifier: EUPL-1.2+ -# SPDX-FileCopyrightText: 2024 Alyssa Ross <hi@alyssa.is> +# SPDX-FileCopyrightText: 2024-2025 Alyssa Ross <hi@alyssa.is>
backtick -E dir { mktemp -d /run/vm/by-id/XXXXXX } backtick -E id { basename -- $dir }
if { mkdir -p /run/configs/${id}/fs } -if { redirfd -w 1 /run/configs/${id}/fs/type echo appimage } -if { touch /run/configs/${id}/fs/run } -if { mount --rbind $1 /run/configs/${id}/fs/run } + if { ln -s /usr/lib/spectrum/img/appvm/blk /usr/lib/spectrum/img/appvm/vmlinux /run/configs/${id} @@ -18,6 +16,14 @@ if { ln -s /run/configs/${id} ${dir}/config }
if { create-vm-dependencies $id }
+if { + nsenter --mount=${dir}/mount + cd ${dir}/fs/config + if { redirfd -w 1 type echo appimage } + if { touch run } + mount --bind $1 run +} + piperw 4 3 background { fdclose 3 @@ -34,13 +40,6 @@ fdclose 3
if { s6-instance-delete /run/service/vm-services $id }
-if { - forx -E mount { - /run/configs/${id}/fs/run - ${dir}/fs/config - ${dir}/fs/doc - } - umount $mount -} - +if { umount ${dir}/mount } # mount namespace +if { umount ${dir}/mount } # private bind mount rm -r $dir /run/configs/${id}
-- Sincerely, Demi Marie Obenour (she/her/hers)