Re: [libvirt] [PATCH 2/2] lxc: Clean up /.oldroot

On Sun, Apr 15, 2018 at 04:30:11PM +0100, Radostin Stoyanov wrote: > Remove the /.oldroot directory after it has been unmounted (at the end > of lxcContainerSetupPivotRoot). Ignore errors silently. > > Signed-off-by: Radostin Stoyanov <rstoyanov1(a)gmail.com&gt; > --- > src/lxc/lxc_container.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c > index 665b93a0a..dd4e38703 100644 > --- a/src/lxc/lxc_container.c > +++ b/src/lxc/lxc_container.c > @@ -1811,6 +1811,9 @@ static int lxcContainerSetupPivotRoot(virDomainDefPtr vmDef, > if (lxcContainerUnmountSubtree("/.oldroot", true) < 0) > goto cleanup; > > + if (virFileRemove("/.oldroot", 0, 0) < 0) > + VIR_DEBUG("Failed to remove /.oldroot after start"); > + I think this introduces a race condition. There can be two containers with the same root filesystem. If we start both at the same time, then this deletion of /.oldroot can cause the other contanier to fail to start if it saw that /.oldroot already existed & it thus tried to skip mkdir.

Leaving the empty directory is harmless IMHO