diff --git a/drivers/driver_linux.go b/drivers/driver_linux.go index dddf8a8b4c..0fe3eea7ae 100644 --- a/drivers/driver_linux.go +++ b/drivers/driver_linux.go @@ -50,6 +50,40 @@ const ( FsMagicOverlay = FsMagic(0x794C7630) // FsMagicFUSE filesystem id for FUSE FsMagicFUSE = FsMagic(0x65735546) + // FsMagicAcfs filesystem id for Acfs + FsMagicAcfs = FsMagic(0x61636673) + // FsMagicAfs filesystem id for Afs + FsMagicAfs = FsMagic(0x5346414f) + // FsMagicCephFs filesystem id for Ceph + FsMagicCephFs = FsMagic(0x00C36400) + // FsMagicCIFS filesystem id for CIFS + FsMagicCIFS = FsMagic(0xFF534D42) + // FsMagicFHGFS filesystem id for FHGFS + FsMagicFHGFSFs = FsMagic(0x19830326) + // FsMagicIBRIX filesystem id for IBRIX + FsMagicIBRIX = FsMagic(0x013111A8) + // FsMagicKAFS filesystem id for KAFS + FsMagicKAFS = FsMagic(0x6B414653) + // FsMagicLUSTRE filesystem id for LUSTRE + FsMagicLUSTRE = FsMagic(0x0BD00BD0) + // FsMagicNCP filesystem id for NCP + FsMagicNCP = FsMagic(0x564C) + // FsMagicNFSD filesystem id for NFSD + FsMagicNFSD = FsMagic(0x6E667364) + // FsMagicOCFS2 filesystem id for OCFS2 + FsMagicOCFS2 = FsMagic(0x7461636F) + // FsMagicPANFS filesystem id for PANFS + FsMagicPANFS = FsMagic(0xAAD7AAEA) + // FsMagicPRLFS filesystem id for PRLFS + FsMagicPRLFS = FsMagic(0x7C7C6673) + // FsMagicSMB2 filesystem id for SMB2 + FsMagicSMB2 = FsMagic(0xFE534D42) + // FsMagicSNFS filesystem id for SNFS + FsMagicSNFS = FsMagic(0xBEEFDEAD) + // FsMagicVBOXSF filesystem id for VBOXSF + FsMagicVBOXSF = FsMagic(0x786F4256) + // FsMagicVXFS filesystem id for VXFS + FsMagicVXFS = FsMagic(0xA501FCF5) ) var ( diff --git a/drivers/overlay/overlay.go b/drivers/overlay/overlay.go index 62130c73e7..1efe7316d3 100644 --- a/drivers/overlay/overlay.go +++ b/drivers/overlay/overlay.go @@ -248,6 +248,23 @@ func (d *Driver) getSupportsVolatile() (bool, error) { return supportsVolatile, nil } +// isNetworkFileSystem checks if the specified file system is supported by native overlay +// as backing store when running in a user namespace. +func isNetworkFileSystem(fsMagic graphdriver.FsMagic) bool { + switch fsMagic { + // a bunch of network file systems... + case graphdriver.FsMagicNfsFs, graphdriver.FsMagicSmbFs, graphdriver.FsMagicAcfs, + graphdriver.FsMagicAfs, graphdriver.FsMagicCephFs, graphdriver.FsMagicCIFS, + graphdriver.FsMagicFHGFSFs, graphdriver.FsMagicGPFS, graphdriver.FsMagicIBRIX, + graphdriver.FsMagicKAFS, graphdriver.FsMagicLUSTRE, graphdriver.FsMagicNCP, + graphdriver.FsMagicNFSD, graphdriver.FsMagicOCFS2, graphdriver.FsMagicPANFS, + graphdriver.FsMagicPRLFS, graphdriver.FsMagicSMB2, graphdriver.FsMagicSNFS, + graphdriver.FsMagicVBOXSF, graphdriver.FsMagicVXFS: + return true + } + return false +} + // Init returns the a native diff driver for overlay filesystem. // If overlay filesystem is not supported on the host, a wrapped graphdriver.ErrNotSupported is returned as error. // If an overlay filesystem is not supported over an existing filesystem then a wrapped graphdriver.ErrIncompatibleFS is returned. @@ -266,18 +283,27 @@ func Init(home string, options graphdriver.Options) (graphdriver.Driver, error) } if opts.mountProgram != "" { + if unshare.IsRootless() && isNetworkFileSystem(fsMagic) && opts.forceMask == nil { + m := os.FileMode(0700) + opts.forceMask = &m + logrus.Warnf("Network file system detected as backing store. Enforcing overlay option `force_mask=\"%o\"`. Add it to storage.conf to silence this warning", m) + } + if err := ioutil.WriteFile(getMountProgramFlagFile(home), []byte("true"), 0600); err != nil { return nil, err } } else { - // check if they are running over btrfs, aufs, zfs, overlay, or ecryptfs if opts.forceMask != nil { return nil, errors.New("'force_mask' is supported only with 'mount_program'") } + // check if they are running over btrfs, aufs, zfs, overlay, or ecryptfs switch fsMagic { case graphdriver.FsMagicAufs, graphdriver.FsMagicZfs, graphdriver.FsMagicOverlay, graphdriver.FsMagicEcryptfs: return nil, errors.Wrapf(graphdriver.ErrIncompatibleFS, "'overlay' is not supported over %s, a mount_program is required", backingFs) } + if unshare.IsRootless() && isNetworkFileSystem(fsMagic) { + return nil, errors.Wrapf(graphdriver.ErrIncompatibleFS, "A network file system with user namespaces is not supported. Please use a mount_program") + } } rootUID, rootGID, err := idtools.GetRootUIDGID(options.UIDMaps, options.GIDMaps) @@ -1431,6 +1457,11 @@ func (d *Driver) get(id string, disableShifting bool, options graphdriver.MountO label = d.optsAppendMappings(label, options.UidMaps, options.GidMaps) } + // if forceMask is in place, tell fuse-overlayfs to write the permissions mask to an unprivileged xattr as well. + if d.options.forceMask != nil { + label = label + ",xattr_permissions=2" + } + mountProgram := exec.Command(d.options.mountProgram, "-o", label, target) mountProgram.Dir = d.home var b bytes.Buffer diff --git a/pkg/system/syscall_unix.go b/pkg/system/syscall_unix.go index 49dbdd3781..1bb852d11f 100644 --- a/pkg/system/syscall_unix.go +++ b/pkg/system/syscall_unix.go @@ -1,8 +1,11 @@ -// +build linux freebsd +// +build linux freebsd darwin package system -import "golang.org/x/sys/unix" +import ( + "github.com/pkg/errors" + "golang.org/x/sys/unix" +) // Unmount is a platform-specific helper function to call // the unmount syscall. @@ -15,3 +18,8 @@ func Unmount(dest string) error { func CommandLineToArgv(commandLine string) ([]string, error) { return []string{commandLine}, nil } + +// IsEBUSY checks if the specified error is EBUSY. +func IsEBUSY(err error) bool { + return errors.Is(err, unix.EBUSY) +} diff --git a/pkg/system/syscall_windows.go b/pkg/system/syscall_windows.go index 23e9b207c7..f4d8692cdb 100644 --- a/pkg/system/syscall_windows.go +++ b/pkg/system/syscall_windows.go @@ -120,3 +120,8 @@ func HasWin32KSupport() bool { // APIs. return ntuserApiset.Load() == nil } + +// IsEBUSY checks if the specified error is EBUSY. +func IsEBUSY(err error) bool { + return false +} diff --git a/store.go b/store.go index 6f6f698072..169c7d1513 100644 --- a/store.go +++ b/store.go @@ -23,6 +23,7 @@ import ( "github.com/containers/storage/pkg/parsers" "github.com/containers/storage/pkg/stringid" "github.com/containers/storage/pkg/stringutils" + "github.com/containers/storage/pkg/system" "github.com/containers/storage/types" "github.com/hashicorp/go-multierror" digest "github.com/opencontainers/go-digest" @@ -2498,7 +2499,15 @@ func (s *store) DeleteContainer(id string) error { gcpath := filepath.Join(s.GraphRoot(), middleDir, container.ID) wg.Add(1) go func() { - errChan <- os.RemoveAll(gcpath) + var err error + for attempts := 0; attempts < 50; attempts++ { + err = os.RemoveAll(gcpath) + if err == nil || !system.IsEBUSY(err) { + break + } + time.Sleep(time.Millisecond * 100) + } + errChan <- err wg.Done() }()