Files
docker-cli/components/engine/daemon/volumes_windows.go
T
Brian Goff 7cb8389345 Use rslave propagation for mounts from daemon root
By default, if a user requests a bind mount it uses private propagation.
When the source path is a path within the daemon root this, along with
some other propagation values that the user can use, causes issues when
the daemon tries to remove a mountpoint because a container will then
have a private reference to that mount which prevents removal.

Unmouting with MNT_DETATCH can help this scenario on newer kernels, but
ultimately this is just covering up the problem and doesn't actually
free up the underlying resources until all references are destroyed.

This change does essentially 2 things:

1. Change the default propagation when unspecified to `rslave` when the
source path is within the daemon root path or a parent of the daemon
root (because everything is using rbinds).
2. Creates a validation error on create when the user tries to specify
an unacceptable propagation mode for these paths...
basically the only two acceptable modes are `rslave` and `rshared`.

In cases where we have used the new default propagation but the
underlying filesystem is not setup to handle it (fs must hvae at least
rshared propagation) instead of erroring out like we normally would,
this falls back to the old default mode of `private`, which preserves
backwards compatibility.

Signed-off-by: Brian Goff <cpuguy83@gmail.com>
(cherry picked from commit 589a0afa8cbe39b6512662fd1705873e2d236dd0)
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
2018-02-15 10:20:07 -05:00

54 lines
1.5 KiB
Go

// +build windows
package daemon
import (
"sort"
"github.com/docker/docker/api/types/mount"
"github.com/docker/docker/container"
"github.com/docker/docker/pkg/idtools"
"github.com/docker/docker/volume"
)
// setupMounts configures the mount points for a container by appending each
// of the configured mounts on the container to the OCI mount structure
// which will ultimately be passed into the oci runtime during container creation.
// It also ensures each of the mounts are lexicographically sorted.
// BUGBUG TODO Windows containerd. This would be much better if it returned
// an array of runtime spec mounts, not container mounts. Then no need to
// do multiple transitions.
func (daemon *Daemon) setupMounts(c *container.Container) ([]container.Mount, error) {
var mnts []container.Mount
for _, mount := range c.MountPoints { // type is volume.MountPoint
if err := daemon.lazyInitializeVolume(c.ID, mount); err != nil {
return nil, err
}
s, err := mount.Setup(c.MountLabel, idtools.IDPair{0, 0}, nil)
if err != nil {
return nil, err
}
mnts = append(mnts, container.Mount{
Source: s,
Destination: mount.Destination,
Writable: mount.RW,
})
}
sort.Sort(mounts(mnts))
return mnts, nil
}
// setBindModeIfNull is platform specific processing which is a no-op on
// Windows.
func setBindModeIfNull(bind *volume.MountPoint) {
return
}
func (daemon *Daemon) validateBindDaemonRoot(m mount.Mount) (bool, error) {
return false, nil
}