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When rootfsPropagation is set to rslave, prepareRoot() was forcing the rootfs parent mount to MS_PRIVATE before bind-mounting and pivoting into the rootfs. That breaks the slave relationship needed for HostToContainer propagation, so later unmount/remount events on host mountpoints under the rootfs are not reflected inside the running container. Fix this by keeping the rootfs parent mount as MS_SLAVE for slave-like rootfs propagation settings, while leaving the final root propagation remount in place. Signed-off-by: sean <xujihui1985@gmail.com> (cherry picked from commit ec170d8) Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
add bat integration test for rootfs propagation test, expect to see the mount propagation is slave, the test will create a isolate mntns to run the test as the test will mutate the rootfs propagation Signed-off-by: sean <xujihui1985@gmail.com> (cherry picked from commit 38245cc) Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
AkihiroSuda
approved these changes
Sep 14, 2026
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Backport of #5200 to release-1.5. Original description follows.
When rootfsPropagation is set to rslave, prepareRoot() was forcing the rootfs parent mount to MS_PRIVATE before bind-mounting and pivoting into the rootfs. That breaks the slave relationship needed for HostToContainer propagation, so later unmount/remount events on host mountpoints under the rootfs are not reflected inside the running container.
Fix this by keeping the rootfs parent mount as MS_SLAVE for slave-like rootfs propagation settings, while leaving the final root propagation remount in place.
Fixes: #5192