func clearReadOnly(m *specs.Mount) {
var opt []string
for _, o := range m.Options {
if o != "ro" {
opt = append(opt, o)
}
}
m.Options = opt
}
func setMounts(daemon *Daemon, s *specs.Spec, c *container.Container, mounts []container.Mount) error {
userMounts := make(map[string]struct{})
for _, m := range mounts {
userMounts[m.Destination] = struct{}{}
}
// Filter out mounts that are overridden by user supplied mounts
var defaultMounts []specs.Mount
_, mountDev := userMounts["/dev"]
for _, m := range s.Mounts {
if _, ok := userMounts[m.Destination]; !ok {
if mountDev && strings.HasPrefix(m.Destination, "/dev/") {
continue
}
defaultMounts = append(defaultMounts, m)
}
}
s.Mounts = defaultMounts
for _, m := range mounts {
for _, cm := range s.Mounts {
if cm.Destination == m.Destination {
return fmt.Errorf("Duplicate mount point '%s'", m.Destination)
}
}
if m.Source == "tmpfs" {
data := m.Data
options := []string{"noexec", "nosuid", "nodev", string(volume.DefaultPropagationMode)}
if data != "" {
options = append(options, strings.Split(data, ",")...)
}
merged, err := mount.MergeTmpfsOptions(options)
if err != nil {
return err
}
s.Mounts = append(s.Mounts, specs.Mount{Destination: m.Destination, Source: m.Source, Type: "tmpfs", Options: merged})
continue
}
mt := specs.Mount{Destination: m.Destination, Source: m.Source, Type: "bind"}
// Determine property of RootPropagation based on volume
// properties. If a volume is shared, then keep root propagation
// shared. This should work for slave and private volumes too.
//
// For slave volumes, it can be either [r]shared/[r]slave.
//
// For private volumes any root propagation value should work.
pFlag := mountPropagationMap[m.Propagation]
if pFlag == mount.SHARED || pFlag == mount.RSHARED {
if err := ensureShared(m.Source); err != nil {
return err
}
rootpg := mountPropagationMap[s.Linux.RootfsPropagation]
if rootpg != mount.SHARED && rootpg != mount.RSHARED {
s.Linux.RootfsPropagation = mountPropagationReverseMap[mount.SHARED]
}
} else if pFlag == mount.SLAVE || pFlag == mount.RSLAVE {
if err := ensureSharedOrSlave(m.Source); err != nil {
return err
}
rootpg := mountPropagationMap[s.Linux.RootfsPropagation]
if rootpg != mount.SHARED && rootpg != mount.RSHARED && rootpg != mount.SLAVE && rootpg != mount.RSLAVE {
s.Linux.RootfsPropagation = mountPropagationReverseMap[mount.RSLAVE]
}
}
opts := []string{"rbind"}
if !m.Writable {
opts = append(opts, "ro")
}
if pFlag != 0 {
opts = append(opts, mountPropagationReverseMap[pFlag])
}
mt.Options = opts
s.Mounts = append(s.Mounts, mt)
}
if s.Root.Readonly {
for i, m := range s.Mounts {
switch m.Destination {
case "/proc", "/dev/pts", "/dev/mqueue": // /dev is remounted by runc
continue
}
if _, ok := userMounts[m.Destination]; !ok {
if !stringutils.InSlice(m.Options, "ro") {
s.Mounts[i].Options = append(s.Mounts[i].Options, "ro")
}
}
}
}
if c.HostConfig.Privileged {
if !s.Root.Readonly {
// clear readonly for /sys
for i := range s.Mounts {
if s.Mounts[i].Destination == "/sys" {
clearReadOnly(&s.Mounts[i])
}
}
}
s.Linux.ReadonlyPaths = nil
s.Linux.MaskedPaths = nil
}
// TODO: until a kernel/mount solution exists for handling remount in a user namespace,
// we must clear the readonly flag for the cgroups mount (@mrunalp concurs)
if uidMap, _ := daemon.GetUIDGIDMaps(); uidMap != nil || c.HostConfig.Privileged {
for i, m := range s.Mounts {
if m.Type == "cgroup" {
clearReadOnly(&s.Mounts[i])
}
}
}
return nil
}