diff --git a/libcontainer/rootfs_linux.go b/libcontainer/rootfs_linux.go index 72aa3af20..e4a4df20c 100644 --- a/libcontainer/rootfs_linux.go +++ b/libcontainer/rootfs_linux.go @@ -1331,16 +1331,14 @@ func verifyDevNull(f *os.File) error { // maskDir mounts a read-only tmpfs on top of the specified path. func maskDir(path, mountLabel string) error { - // On most kernels `nr_inodes=1` works fine. However, Ubuntu 20.04 (Focal) with - // the official 5.4 kernel carries a private patch in mm/shmem.c that rejects - // "nr_inodes<2", so let's keep `nr_inodes=2` here! - // For reference, search for "case Opt_nr_inodes" in: - // https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/plain/mm/shmem.c?h=Ubuntu-5.4.0-216.236 - err := mount("tmpfs", path, "tmpfs", unix.MS_RDONLY, label.FormatMountLabel("nr_blocks=1,nr_inodes=2", mountLabel)) - // We don't know whether some kernels will fail with "nr_inodes=2", - // so let's fall back to mount a tmpfs without this option. - if errors.Is(err, unix.EINVAL) { - err = mount("tmpfs", path, "tmpfs", unix.MS_RDONLY, label.FormatMountLabel("nr_blocks=1", mountLabel)) + err := mount("tmpfs", path, "tmpfs", unix.MS_RDONLY, label.FormatMountLabel("nr_blocks=1,nr_inodes=1", mountLabel)) + if err != nil { + // On most kernels `nr_inodes=1` works fine. However, Ubuntu 20.04 (Focal) with + // the official 5.4 kernel carries a private patch in "mm/shmem.c" that rejects + // `nr_inodes<2`, so retry with `nr_inodes=2` here. + // For reference, search for "case Opt_nr_inodes" in: + // https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/plain/mm/shmem.c?h=Ubuntu-5.4.0-216.236 + err = mount("tmpfs", path, "tmpfs", unix.MS_RDONLY, label.FormatMountLabel("nr_blocks=1,nr_inodes=2", mountLabel)) } return err }