From 0f6b0e8c9ca3bfa944294a0de98869d732988893 Mon Sep 17 00:00:00 2001 From: Matthew Heon Date: Mon, 14 Oct 2019 10:29:54 -0400 Subject: Ensure volumes can be removed when they fail to unmount Also, ensure that we don't try to mount them without root - it appears that it can somehow not error and report that mount was successful when it clearly did not succeed, which can induce this case. We reuse the `--force` flag to indicate that a volume should be removed even after unmount errors. It seems fairly natural to expect that --force will remove a volume that is otherwise presenting problems. Finally, ignore EINVAL on unmount - if the mount point no longer exists our job is done. Fixes: #4247 Fixes: #4248 Signed-off-by: Matthew Heon --- libpod/define/errors.go | 4 ++++ libpod/runtime_volume_linux.go | 9 ++++++++- libpod/volume_internal_linux.go | 25 +++++++++++++++++++++++++ 3 files changed, 37 insertions(+), 1 deletion(-) (limited to 'libpod') diff --git a/libpod/define/errors.go b/libpod/define/errors.go index 5392fbc62..523062866 100644 --- a/libpod/define/errors.go +++ b/libpod/define/errors.go @@ -65,6 +65,10 @@ var ( // CGroup. ErrNoCgroups = errors.New("this container does not have a cgroup") + // ErrRootless indicates that the given command cannot but run without + // root. + ErrRootless = errors.New("operation requires root privileges") + // ErrRuntimeStopped indicates that the runtime has already been shut // down and no further operations can be performed on it ErrRuntimeStopped = errors.New("runtime has already been stopped") diff --git a/libpod/runtime_volume_linux.go b/libpod/runtime_volume_linux.go index 9df93faf3..ba4fff4be 100644 --- a/libpod/runtime_volume_linux.go +++ b/libpod/runtime_volume_linux.go @@ -157,7 +157,14 @@ func (r *Runtime) removeVolume(ctx context.Context, v *Volume, force bool) error // If the volume is still mounted - force unmount it if err := v.unmount(true); err != nil { - return errors.Wrapf(err, "error unmounting volume %s", v.Name()) + if force { + // If force is set, evict the volume, even if errors + // occur. Otherwise we'll never be able to get rid of + // them. + logrus.Errorf("Error unmounting volume %s: %v", v.Name(), err) + } else { + return errors.Wrapf(err, "error unmounting volume %s", v.Name()) + } } // Set volume as invalid so it can no longer be used diff --git a/libpod/volume_internal_linux.go b/libpod/volume_internal_linux.go index 9ae4dcf69..4c0332018 100644 --- a/libpod/volume_internal_linux.go +++ b/libpod/volume_internal_linux.go @@ -6,6 +6,8 @@ import ( "io/ioutil" "os/exec" + "github.com/containers/libpod/libpod/define" + "github.com/containers/libpod/pkg/rootless" "github.com/pkg/errors" "github.com/sirupsen/logrus" "golang.org/x/sys/unix" @@ -24,6 +26,11 @@ func (v *Volume) mount() error { return nil } + // We cannot mount volumes as rootless. + if rootless.IsRootless() { + return errors.Wrapf(define.ErrRootless, "cannot mount volumes without root privileges") + } + // Update the volume from the DB to get an accurate mount counter. if err := v.update(); err != nil { return err @@ -108,6 +115,20 @@ func (v *Volume) unmount(force bool) error { return nil } + // We cannot unmount volumes as rootless. + if rootless.IsRootless() { + // If force is set, just clear the counter and bail without + // error, so we can remove volumes from the state if they are in + // an awkward configuration. + if force { + logrus.Errorf("Volume %s is mounted despite being rootless - state is not sane", v.Name()) + v.state.MountCount = 0 + return v.save() + } + + return errors.Wrapf(define.ErrRootless, "cannot mount or unmount volumes without root privileges") + } + if !force { v.state.MountCount = v.state.MountCount - 1 } else { @@ -119,6 +140,10 @@ func (v *Volume) unmount(force bool) error { if v.state.MountCount == 0 { // Unmount the volume if err := unix.Unmount(v.config.MountPoint, unix.MNT_DETACH); err != nil { + if err == unix.EINVAL { + // Ignore EINVAL - the mount no longer exists. + return nil + } return errors.Wrapf(err, "error unmounting volume %s", v.Name()) } logrus.Debugf("Unmounted volume %s", v.Name()) -- cgit v1.2.3-54-g00ecf