diff --git a/runsc/boot/fs.go b/runsc/boot/fs.go index 34c674840..393c2a88b 100644 --- a/runsc/boot/fs.go +++ b/runsc/boot/fs.go @@ -64,6 +64,9 @@ const ( nonefs = "none" ) +// tmpfs has some extra supported options that we must pass through. +var tmpfsAllowedOptions = []string{"mode", "uid", "gid"} + func addOverlay(ctx context.Context, conf *Config, lower *fs.Inode, name string, lowerFlags fs.MountSourceFlags) (*fs.Inode, error) { // Upper layer uses the same flags as lower, but it must be read-write. upperFlags := lowerFlags @@ -172,27 +175,25 @@ func p9MountOptions(fd int, fa FileAccessType) []string { func parseAndFilterOptions(opts []string, allowedKeys ...string) ([]string, error) { var out []string for _, o := range opts { - kv := strings.Split(o, "=") - switch len(kv) { - case 1: - if specutils.ContainsStr(allowedKeys, o) { - out = append(out, o) - continue - } - log.Warningf("ignoring unsupported key %q", kv) - case 2: - if specutils.ContainsStr(allowedKeys, kv[0]) { - out = append(out, o) - continue - } - log.Warningf("ignoring unsupported key %q", kv[0]) - default: - return nil, fmt.Errorf("invalid option %q", o) + ok, err := parseMountOption(o, allowedKeys...) + if err != nil { + return nil, err + } + if ok { + out = append(out, o) } } return out, nil } +func parseMountOption(opt string, allowedKeys ...string) (bool, error) { + kv := strings.SplitN(opt, "=", 3) + if len(kv) > 2 { + return false, fmt.Errorf("invalid option %q", opt) + } + return specutils.ContainsStr(allowedKeys, kv[0]), nil +} + // mountDevice returns a device string based on the fs type and target // of the mount. func mountDevice(m specs.Mount) string { @@ -207,6 +208,8 @@ func mountDevice(m specs.Mount) string { func mountFlags(opts []string) fs.MountSourceFlags { mf := fs.MountSourceFlags{} + // Note: changes to supported options must be reflected in + // isSupportedMountFlag() as well. for _, o := range opts { switch o { case "rw": @@ -224,6 +227,18 @@ func mountFlags(opts []string) fs.MountSourceFlags { return mf } +func isSupportedMountFlag(fstype, opt string) bool { + switch opt { + case "rw", "ro", "noatime", "noexec": + return true + } + if fstype == tmpfs { + ok, err := parseMountOption(opt, tmpfsAllowedOptions...) + return ok && err == nil + } + return false +} + func mustFindFilesystem(name string) fs.Filesystem { fs, ok := fs.FindFilesystem(name) if !ok { @@ -427,6 +442,39 @@ func (m *mountHint) isSupported() bool { return m.mount.Type == tmpfs && m.share == pod } +// checkCompatible verifies that shared mount is compatible with master. +// For now enforce that all options are the same. Once bind mount is properly +// supported, then we should ensure the master is less restrictive than the +// container, e.g. master can be 'rw' while container mounts as 'ro'. +func (m *mountHint) checkCompatible(mount specs.Mount) error { + // Remove options that don't affect to mount's behavior. + masterOpts := filterUnsupportedOptions(m.mount) + slaveOpts := filterUnsupportedOptions(mount) + + if len(masterOpts) != len(slaveOpts) { + return fmt.Errorf("mount options in annotations differ from container mount, annotation: %s, mount: %s", masterOpts, slaveOpts) + } + + sort.Strings(masterOpts) + sort.Strings(slaveOpts) + for i, opt := range masterOpts { + if opt != slaveOpts[i] { + return fmt.Errorf("mount options in annotations differ from container mount, annotation: %s, mount: %s", masterOpts, slaveOpts) + } + } + return nil +} + +func filterUnsupportedOptions(mount specs.Mount) []string { + rv := make([]string, 0, len(mount.Options)) + for _, o := range mount.Options { + if isSupportedMountFlag(mount.Type, o) { + rv = append(rv, o) + } + } + return rv +} + // podMountHints contains a collection of mountHints for the pod. type podMountHints struct { mounts map[string]*mountHint @@ -699,9 +747,7 @@ func (c *containerMounter) getMountNameAndOptions(conf *Config, m specs.Mount) ( fsName = sysfs case tmpfs: fsName = m.Type - - // tmpfs has some extra supported options that we must pass through. - opts, err = parseAndFilterOptions(m.Options, "mode", "uid", "gid") + opts, err = parseAndFilterOptions(m.Options, tmpfsAllowedOptions...) case bind: fd := c.fds.remove() @@ -786,17 +832,8 @@ func (c *containerMounter) mountSubmount(ctx context.Context, conf *Config, mns // mountSharedSubmount binds mount to a previously mounted volume that is shared // among containers in the same pod. func (c *containerMounter) mountSharedSubmount(ctx context.Context, mns *fs.MountNamespace, root *fs.Dirent, mount specs.Mount, source *mountHint) error { - // For now enforce that all options are the same. Once bind mount is properly - // supported, then we should ensure the master is less restrictive than the - // container, e.g. master can be 'rw' while container mounts as 'ro'. - if len(mount.Options) != len(source.mount.Options) { - return fmt.Errorf("mount options in annotations differ from container mount, annotation: %s, mount: %s", source.mount.Options, mount.Options) - } - sort.Strings(mount.Options) - for i, opt := range mount.Options { - if opt != source.mount.Options[i] { - return fmt.Errorf("mount options in annotations differ from container mount, annotation: %s, mount: %s", source.mount.Options, mount.Options) - } + if err := source.checkCompatible(mount); err != nil { + return err } maxTraversals := uint(0)