diff options
Diffstat (limited to 'runsc/boot/vfs.go')
-rw-r--r-- | runsc/boot/vfs.go | 135 |
1 files changed, 113 insertions, 22 deletions
diff --git a/runsc/boot/vfs.go b/runsc/boot/vfs.go index b68117867..9a1ed8e9e 100644 --- a/runsc/boot/vfs.go +++ b/runsc/boot/vfs.go @@ -43,7 +43,11 @@ import ( "gvisor.dev/gvisor/pkg/syserror" ) -func registerFilesystems(ctx context.Context, vfsObj *vfs.VirtualFilesystem, creds *auth.Credentials) error { +func registerFilesystems(k *kernel.Kernel) error { + ctx := k.SupervisorContext() + creds := auth.NewRootCredentials(k.RootUserNamespace()) + vfsObj := k.VFS() + vfsObj.MustRegisterFilesystemType(devpts.Name, &devpts.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ AllowUserList: true, // TODO(b/29356795): Users may mount this once the terminals are in a @@ -73,6 +77,10 @@ func registerFilesystems(ctx context.Context, vfsObj *vfs.VirtualFilesystem, cre AllowUserMount: true, AllowUserList: true, }) + vfsObj.MustRegisterFilesystemType(fuse.Name, &fuse.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ + AllowUserMount: true, + AllowUserList: true, + }) // Setup files in devtmpfs. if err := memdev.Register(vfsObj); err != nil { @@ -82,9 +90,12 @@ func registerFilesystems(ctx context.Context, vfsObj *vfs.VirtualFilesystem, cre return fmt.Errorf("registering ttydev: %w", err) } - if err := fuse.Register(vfsObj); err != nil { - return fmt.Errorf("registering fusedev: %w", err) + if kernel.FUSEEnabled { + if err := fuse.Register(vfsObj); err != nil { + return fmt.Errorf("registering fusedev: %w", err) + } } + if err := tundev.Register(vfsObj); err != nil { return fmt.Errorf("registering tundev: %v", err) } @@ -106,16 +117,17 @@ func registerFilesystems(ctx context.Context, vfsObj *vfs.VirtualFilesystem, cre if err := tundev.CreateDevtmpfsFiles(ctx, a); err != nil { return fmt.Errorf("creating tundev devtmpfs files: %v", err) } - if err := fuse.CreateDevtmpfsFile(ctx, a); err != nil { - return fmt.Errorf("creating fusedev devtmpfs files: %w", err) + + if kernel.FUSEEnabled { + if err := fuse.CreateDevtmpfsFile(ctx, a); err != nil { + return fmt.Errorf("creating fusedev devtmpfs files: %w", err) + } } + return nil } func setupContainerVFS2(ctx context.Context, conf *Config, mntr *containerMounter, procArgs *kernel.CreateProcessArgs) error { - if err := mntr.k.VFS().Init(); err != nil { - return fmt.Errorf("failed to initialize VFS: %w", err) - } mns, err := mntr.setupVFS2(ctx, conf, procArgs) if err != nil { return fmt.Errorf("failed to setupFS: %w", err) @@ -144,10 +156,6 @@ func (c *containerMounter) setupVFS2(ctx context.Context, conf *Config, procArgs rootProcArgs.MaxSymlinkTraversals = linux.MaxSymlinkTraversals rootCtx := procArgs.NewContext(c.k) - if err := registerFilesystems(rootCtx, c.k.VFS(), rootCreds); err != nil { - return nil, fmt.Errorf("register filesystems: %w", err) - } - mns, err := c.createMountNamespaceVFS2(rootCtx, conf, rootCreds) if err != nil { return nil, fmt.Errorf("creating mount namespace: %w", err) @@ -182,8 +190,14 @@ func (c *containerMounter) mountSubmountsVFS2(ctx context.Context, conf *Config, for i := range mounts { submount := &mounts[i] log.Debugf("Mounting %q to %q, type: %s, options: %s", submount.Source, submount.Destination, submount.Type, submount.Options) - if err := c.mountSubmountVFS2(ctx, conf, mns, creds, submount); err != nil { - return err + if hint := c.hints.findMount(submount.Mount); hint != nil && hint.isSupported() { + if err := c.mountSharedSubmountVFS2(ctx, conf, mns, creds, submount.Mount, hint); err != nil { + return fmt.Errorf("mount shared mount %q to %q: %v", hint.name, submount.Destination, err) + } + } else { + if err := c.mountSubmountVFS2(ctx, conf, mns, creds, submount); err != nil { + return fmt.Errorf("mount submount %q: %w", submount.Destination, err) + } } } @@ -257,20 +271,18 @@ func (c *containerMounter) mountSubmountVFS2(ctx context.Context, conf *Config, // getMountNameAndOptionsVFS2 retrieves the fsName, opts, and useOverlay values // used for mounts. func (c *containerMounter) getMountNameAndOptionsVFS2(conf *Config, m *mountAndFD) (string, *vfs.MountOptions, error) { - var ( - fsName string - data []string - ) + fsName := m.Type + var data []string // Find filesystem name and FS specific data field. switch m.Type { case devpts.Name, devtmpfs.Name, proc.Name, sys.Name: - fsName = m.Type + // Nothing to do. + case nonefs: fsName = sys.Name - case tmpfs.Name: - fsName = m.Type + case tmpfs.Name: var err error data, err = parseAndFilterOptions(m.Options, tmpfsAllowedData...) if err != nil { @@ -279,10 +291,16 @@ func (c *containerMounter) getMountNameAndOptionsVFS2(conf *Config, m *mountAndF case bind: fsName = gofer.Name + if m.fd == 0 { + // Check that an FD was provided to fails fast. Technically FD=0 is valid, + // but unlikely to be correct in this context. + return "", nil, fmt.Errorf("9P mount requires a connection FD") + } data = p9MountData(m.fd, c.getMountAccessType(m.Mount), true /* vfs2 */) default: log.Warningf("ignoring unknown filesystem type %q", m.Type) + return "", nil, nil } opts := &vfs.MountOptions{ @@ -322,7 +340,7 @@ func (c *containerMounter) makeSyntheticMount(ctx context.Context, currentPath s } _, err := c.k.VFS().StatAt(ctx, creds, target, &vfs.StatOptions{}) if err == nil { - // Mount point exists, nothing else to do. + log.Debugf("Mount point %q already exists", currentPath) return nil } if err != syserror.ENOENT { @@ -400,3 +418,76 @@ func (c *containerMounter) mountTmpVFS2(ctx context.Context, conf *Config, creds return fmt.Errorf(`stating "/tmp" inside container: %w`, err) } } + +// processHintsVFS2 processes annotations that container hints about how volumes +// should be mounted (e.g. a volume shared between containers). It must be +// called for the root container only. +func (c *containerMounter) processHintsVFS2(conf *Config, creds *auth.Credentials) error { + ctx := c.k.SupervisorContext() + for _, hint := range c.hints.mounts { + // TODO(b/142076984): Only support tmpfs for now. Bind mounts require a + // common gofer to mount all shared volumes. + if hint.mount.Type != tmpfs.Name { + continue + } + + log.Infof("Mounting master of shared mount %q from %q type %q", hint.name, hint.mount.Source, hint.mount.Type) + mnt, err := c.mountSharedMasterVFS2(ctx, conf, hint, creds) + if err != nil { + return fmt.Errorf("mounting shared master %q: %v", hint.name, err) + } + hint.vfsMount = mnt + } + return nil +} + +// mountSharedMasterVFS2 mounts the master of a volume that is shared among +// containers in a pod. +func (c *containerMounter) mountSharedMasterVFS2(ctx context.Context, conf *Config, hint *mountHint, creds *auth.Credentials) (*vfs.Mount, error) { + // Map mount type to filesystem name, and parse out the options that we are + // capable of dealing with. + mntFD := &mountAndFD{Mount: hint.mount} + fsName, opts, err := c.getMountNameAndOptionsVFS2(conf, mntFD) + if err != nil { + return nil, err + } + if len(fsName) == 0 { + return nil, fmt.Errorf("mount type not supported %q", hint.mount.Type) + } + return c.k.VFS().MountDisconnected(ctx, creds, "", fsName, opts) +} + +// mountSharedSubmount binds mount to a previously mounted volume that is shared +// among containers in the same pod. +func (c *containerMounter) mountSharedSubmountVFS2(ctx context.Context, conf *Config, mns *vfs.MountNamespace, creds *auth.Credentials, mount specs.Mount, source *mountHint) error { + if err := source.checkCompatible(mount); err != nil { + return err + } + + _, opts, err := c.getMountNameAndOptionsVFS2(conf, &mountAndFD{Mount: mount}) + if err != nil { + return err + } + newMnt, err := c.k.VFS().NewDisconnectedMount(source.vfsMount.Filesystem(), source.vfsMount.Root(), opts) + if err != nil { + return err + } + defer newMnt.DecRef() + + root := mns.Root() + defer root.DecRef() + if err := c.makeSyntheticMount(ctx, mount.Destination, root, creds); err != nil { + return err + } + + target := &vfs.PathOperation{ + Root: root, + Start: root, + Path: fspath.Parse(mount.Destination), + } + if err := c.k.VFS().ConnectMountAt(ctx, creds, newMnt, target); err != nil { + return err + } + log.Infof("Mounted %q type shared bind to %q", mount.Destination, source.name) + return nil +} |