Plumbing context.Context to DecRef() and Release().

context is passed to DecRef() and Release() which is
needed for SO_LINGER implementation.

PiperOrigin-RevId: 324672584

pkg/refs/BUILD

@@ -24,6 +24,7 @@ go_library(
     ],
     visibility = ["//:sandbox"],
     deps = [
+        "//pkg/context",
         "//pkg/log",
         "//pkg/sync",
     ],
@@ -34,5 +35,8 @@ go_test(
     size = "small",
     srcs = ["refcounter_test.go"],
     library = ":refs",
-    deps = ["//pkg/sync"],
+    deps = [
+        "//pkg/context",
+        "//pkg/sync",
+    ],
 )

pkg/refs/refcounter.go

@@ -23,6 +23,7 @@ import (
 	"runtime"
 	"sync/atomic"
 
+	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/sync"
 )
@@ -38,7 +39,7 @@ type RefCounter interface {
 	// Note that AtomicRefCounter.DecRef() does not support destructors.
 	// If a type has a destructor, it must implement its own DecRef()
 	// method and call AtomicRefCounter.DecRefWithDestructor(destructor).
-	DecRef()
+	DecRef(ctx context.Context)
 
 	// TryIncRef attempts to increase the reference counter on the object,
 	// but may fail if all references have already been dropped. This
@@ -57,7 +58,7 @@ type RefCounter interface {
 // A WeakRefUser is notified when the last non-weak reference is dropped.
 type WeakRefUser interface {
 	// WeakRefGone is called when the last non-weak reference is dropped.
-	WeakRefGone()
+	WeakRefGone(ctx context.Context)
 }
 
 // WeakRef is a weak reference.
@@ -123,7 +124,7 @@ func (w *WeakRef) Get() RefCounter {
 // Drop drops this weak reference. You should always call drop when you are
 // finished with the weak reference. You may not use this object after calling
 // drop.
-func (w *WeakRef) Drop() {
+func (w *WeakRef) Drop(ctx context.Context) {
 	rc, ok := w.get()
 	if !ok {
 		// We've been zapped already. When the refcounter has called
@@ -145,7 +146,7 @@ func (w *WeakRef) Drop() {
 
 	// And now aren't on the object's list of weak references. So it won't
 	// zap us if this causes the reference count to drop to zero.
-	rc.DecRef()
+	rc.DecRef(ctx)
 
 	// Return to the pool.
 	weakRefPool.Put(w)
@@ -427,7 +428,7 @@ func (r *AtomicRefCount) dropWeakRef(w *WeakRef) {
 //	A: TryIncRef [transform speculative to real]
 //
 //go:nosplit
-func (r *AtomicRefCount) DecRefWithDestructor(destroy func()) {
+func (r *AtomicRefCount) DecRefWithDestructor(ctx context.Context, destroy func(context.Context)) {
 	switch v := atomic.AddInt64(&r.refCount, -1); {
 	case v < -1:
 		panic("Decrementing non-positive ref count")
@@ -448,7 +449,7 @@ func (r *AtomicRefCount) DecRefWithDestructor(destroy func()) {
 
 			if user != nil {
 				r.mu.Unlock()
-				user.WeakRefGone()
+				user.WeakRefGone(ctx)
 				r.mu.Lock()
 			}
 		}
@@ -456,7 +457,7 @@ func (r *AtomicRefCount) DecRefWithDestructor(destroy func()) {
 
 		// Call the destructor.
 		if destroy != nil {
-			destroy()
+			destroy(ctx)
 		}
 	}
 }
@@ -464,6 +465,6 @@ func (r *AtomicRefCount) DecRefWithDestructor(destroy func()) {
 // DecRef decrements this object's reference count.
 //
 //go:nosplit
-func (r *AtomicRefCount) DecRef() {
-	r.DecRefWithDestructor(nil)
+func (r *AtomicRefCount) DecRef(ctx context.Context) {
+	r.DecRefWithDestructor(ctx, nil)
 }

pkg/refs/refcounter_test.go

@@ -18,6 +18,7 @@ import (
 	"reflect"
 	"testing"
 
+	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/sync"
 )
 
@@ -31,11 +32,11 @@ type testCounter struct {
 	destroyed bool
 }
 
-func (t *testCounter) DecRef() {
-	t.AtomicRefCount.DecRefWithDestructor(t.destroy)
+func (t *testCounter) DecRef(ctx context.Context) {
+	t.AtomicRefCount.DecRefWithDestructor(ctx, t.destroy)
 }
 
-func (t *testCounter) destroy() {
+func (t *testCounter) destroy(context.Context) {
 	t.mu.Lock()
 	defer t.mu.Unlock()
 	t.destroyed = true
@@ -53,7 +54,7 @@ func newTestCounter() *testCounter {
 
 func TestOneRef(t *testing.T) {
 	tc := newTestCounter()
-	tc.DecRef()
+	tc.DecRef(context.Background())
 
 	if !tc.IsDestroyed() {
 		t.Errorf("object should have been destroyed")
@@ -63,8 +64,9 @@ func TestOneRef(t *testing.T) {
 func TestTwoRefs(t *testing.T) {
 	tc := newTestCounter()
 	tc.IncRef()
-	tc.DecRef()
-	tc.DecRef()
+	ctx := context.Background()
+	tc.DecRef(ctx)
+	tc.DecRef(ctx)
 
 	if !tc.IsDestroyed() {
 		t.Errorf("object should have been destroyed")
@@ -74,12 +76,13 @@ func TestTwoRefs(t *testing.T) {
 func TestMultiRefs(t *testing.T) {
 	tc := newTestCounter()
 	tc.IncRef()
-	tc.DecRef()
+	ctx := context.Background()
+	tc.DecRef(ctx)
 
 	tc.IncRef()
-	tc.DecRef()
+	tc.DecRef(ctx)
 
-	tc.DecRef()
+	tc.DecRef(ctx)
 
 	if !tc.IsDestroyed() {
 		t.Errorf("object should have been destroyed")
@@ -89,19 +92,20 @@ func TestMultiRefs(t *testing.T) {
 func TestWeakRef(t *testing.T) {
 	tc := newTestCounter()
 	w := NewWeakRef(tc, nil)
+	ctx := context.Background()
 
 	// Try resolving.
 	if x := w.Get(); x == nil {
 		t.Errorf("weak reference didn't resolve: expected %v, got nil", tc)
 	} else {
-		x.DecRef()
+		x.DecRef(ctx)
 	}
 
 	// Try resolving again.
 	if x := w.Get(); x == nil {
 		t.Errorf("weak reference didn't resolve: expected %v, got nil", tc)
 	} else {
-		x.DecRef()
+		x.DecRef(ctx)
 	}
 
 	// Shouldn't be destroyed yet. (Can't continue if this fails.)
@@ -110,7 +114,7 @@ func TestWeakRef(t *testing.T) {
 	}
 
 	// Drop the original reference.
-	tc.DecRef()
+	tc.DecRef(ctx)
 
 	// Assert destroyed.
 	if !tc.IsDestroyed() {
@@ -126,7 +130,8 @@ func TestWeakRef(t *testing.T) {
 func TestWeakRefDrop(t *testing.T) {
 	tc := newTestCounter()
 	w := NewWeakRef(tc, nil)
-	w.Drop()
+	ctx := context.Background()
+	w.Drop(ctx)
 
 	// Just assert the list is empty.
 	if !tc.weakRefs.Empty() {
@@ -134,14 +139,14 @@ func TestWeakRefDrop(t *testing.T) {
 	}
 
 	// Drop the original reference.
-	tc.DecRef()
+	tc.DecRef(ctx)
 }
 
 type testWeakRefUser struct {
 	weakRefGone func()
 }
 
-func (u *testWeakRefUser) WeakRefGone() {
+func (u *testWeakRefUser) WeakRefGone(ctx context.Context) {
 	u.weakRefGone()
 }
 
@@ -165,7 +170,8 @@ func TestCallback(t *testing.T) {
 	}})
 
 	// Drop the original reference, this must trigger the callback.
-	tc.DecRef()
+	ctx := context.Background()
+	tc.DecRef(ctx)
 
 	if !called {
 		t.Fatalf("Callback not called")

pkg/sentry/control/proc.go

@@ -139,7 +139,6 @@ func ExecAsync(proc *Proc, args *ExecArgs) (*kernel.ThreadGroup, kernel.ThreadID
 func (proc *Proc) execAsync(args *ExecArgs) (*kernel.ThreadGroup, kernel.ThreadID, *host.TTYFileOperations, *hostvfs2.TTYFileDescription, error) {
 	// Import file descriptors.
 	fdTable := proc.Kernel.NewFDTable()
-	defer fdTable.DecRef()
 
 	creds := auth.NewUserCredentials(
 		args.KUID,
@@ -177,6 +176,7 @@ func (proc *Proc) execAsync(args *ExecArgs) (*kernel.ThreadGroup, kernel.ThreadI
 		initArgs.MountNamespaceVFS2.IncRef()
 	}
 	ctx := initArgs.NewContext(proc.Kernel)
+	defer fdTable.DecRef(ctx)
 
 	if kernel.VFS2Enabled {
 		// Get the full path to the filename from the PATH env variable.

pkg/sentry/devices/memdev/full.go

@@ -46,7 +46,7 @@ type fullFD struct {
 }
 
 // Release implements vfs.FileDescriptionImpl.Release.
-func (fd *fullFD) Release() {
+func (fd *fullFD) Release(context.Context) {
 	// noop
 }
 

pkg/sentry/devices/memdev/null.go

@@ -47,7 +47,7 @@ type nullFD struct {
 }
 
 // Release implements vfs.FileDescriptionImpl.Release.
-func (fd *nullFD) Release() {
+func (fd *nullFD) Release(context.Context) {
 	// noop
 }
 

pkg/sentry/devices/memdev/random.go

@@ -56,7 +56,7 @@ type randomFD struct {
 }
 
 // Release implements vfs.FileDescriptionImpl.Release.
-func (fd *randomFD) Release() {
+func (fd *randomFD) Release(context.Context) {
 	// noop
 }
 

pkg/sentry/devices/memdev/zero.go

@@ -48,7 +48,7 @@ type zeroFD struct {
 }
 
 // Release implements vfs.FileDescriptionImpl.Release.
-func (fd *zeroFD) Release() {
+func (fd *zeroFD) Release(context.Context) {
 	// noop
 }
 

pkg/sentry/devices/ttydev/ttydev.go

@@ -55,7 +55,7 @@ type ttyFD struct {
 }
 
 // Release implements vfs.FileDescriptionImpl.Release.
-func (fd *ttyFD) Release() {}
+func (fd *ttyFD) Release(context.Context) {}
 
 // PRead implements vfs.FileDescriptionImpl.PRead.
 func (fd *ttyFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) {

pkg/sentry/devices/tundev/tundev.go

@@ -108,8 +108,8 @@ func (fd *tunFD) Ioctl(ctx context.Context, uio usermem.IO, args arch.SyscallArg
 }
 
 // Release implements vfs.FileDescriptionImpl.Release.
-func (fd *tunFD) Release() {
-	fd.device.Release()
+func (fd *tunFD) Release(ctx context.Context) {
+	fd.device.Release(ctx)
 }
 
 // PRead implements vfs.FileDescriptionImpl.PRead.

pkg/sentry/fdimport/fdimport.go

@@ -50,7 +50,7 @@ func importFS(ctx context.Context, fdTable *kernel.FDTable, console bool, fds []
 				if err != nil {
 					return nil, err
 				}
-				defer appFile.DecRef()
+				defer appFile.DecRef(ctx)
 
 				// Remember this in the TTY file, as we will
 				// use it for the other stdio FDs.
@@ -69,7 +69,7 @@ func importFS(ctx context.Context, fdTable *kernel.FDTable, console bool, fds []
 			if err != nil {
 				return nil, err
 			}
-			defer appFile.DecRef()
+			defer appFile.DecRef(ctx)
 		}
 
 		// Add the file to the FD map.
@@ -102,7 +102,7 @@ func importVFS2(ctx context.Context, fdTable *kernel.FDTable, console bool, stdi
 				if err != nil {
 					return nil, err
 				}
-				defer appFile.DecRef()
+				defer appFile.DecRef(ctx)
 
 				// Remember this in the TTY file, as we will use it for the other stdio
 				// FDs.
@@ -119,7 +119,7 @@ func importVFS2(ctx context.Context, fdTable *kernel.FDTable, console bool, stdi
 			if err != nil {
 				return nil, err
 			}
-			defer appFile.DecRef()
+			defer appFile.DecRef(ctx)
 		}
 
 		if err := fdTable.NewFDAtVFS2(ctx, int32(appFD), appFile, kernel.FDFlags{}); err != nil {

pkg/sentry/fs/copy_up.go

@@ -201,7 +201,7 @@ func copyUpLocked(ctx context.Context, parent *Dirent, next *Dirent) error {
 	parentUpper := parent.Inode.overlay.upper
 	root := RootFromContext(ctx)
 	if root != nil {
-		defer root.DecRef()
+		defer root.DecRef(ctx)
 	}
 
 	// Create the file in the upper filesystem and get an Inode for it.
@@ -212,7 +212,7 @@ func copyUpLocked(ctx context.Context, parent *Dirent, next *Dirent) error {
 			log.Warningf("copy up failed to create file: %v", err)
 			return syserror.EIO
 		}
-		defer childFile.DecRef()
+		defer childFile.DecRef(ctx)
 		childUpperInode = childFile.Dirent.Inode
 
 	case Directory:
@@ -226,7 +226,7 @@ func copyUpLocked(ctx context.Context, parent *Dirent, next *Dirent) error {
 			cleanupUpper(ctx, parentUpper, next.name, werr)
 			return syserror.EIO
 		}
-		defer childUpper.DecRef()
+		defer childUpper.DecRef(ctx)
 		childUpperInode = childUpper.Inode
 
 	case Symlink:
@@ -246,7 +246,7 @@ func copyUpLocked(ctx context.Context, parent *Dirent, next *Dirent) error {
 			cleanupUpper(ctx, parentUpper, next.name, werr)
 			return syserror.EIO
 		}
-		defer childUpper.DecRef()
+		defer childUpper.DecRef(ctx)
 		childUpperInode = childUpper.Inode
 
 	default:
@@ -352,14 +352,14 @@ func copyContentsLocked(ctx context.Context, upper *Inode, lower *Inode, size in
 	if err != nil {
 		return err
 	}
-	defer upperFile.DecRef()
+	defer upperFile.DecRef(ctx)
 
 	// Get a handle to the lower filesystem, which we will read from.
 	lowerFile, err := overlayFile(ctx, lower, FileFlags{Read: true})
 	if err != nil {
 		return err
 	}
-	defer lowerFile.DecRef()
+	defer lowerFile.DecRef(ctx)
 
 	// Use a buffer pool to minimize allocations.
 	buf := copyUpBuffers.Get().([]byte)

pkg/sentry/fs/copy_up_test.go

@@ -126,7 +126,7 @@ func makeOverlayTestFiles(t *testing.T) []*overlayTestFile {
 		if err != nil {
 			t.Fatalf("failed to create file %q: %v", name, err)
 		}
-		defer f.DecRef()
+		defer f.DecRef(ctx)
 
 		relname, _ := f.Dirent.FullName(lowerRoot)
 
@@ -171,7 +171,7 @@ func makeOverlayTestFiles(t *testing.T) []*overlayTestFile {
 		if err != nil {
 			t.Fatalf("failed to find %q: %v", f.name, err)
 		}
-		defer d.DecRef()
+		defer d.DecRef(ctx)
 
 		f.File, err = d.Inode.GetFile(ctx, d, fs.FileFlags{Read: true})
 		if err != nil {

pkg/sentry/fs/dev/net_tun.go

@@ -80,8 +80,8 @@ type netTunFileOperations struct {
 var _ fs.FileOperations = (*netTunFileOperations)(nil)
 
 // Release implements fs.FileOperations.Release.
-func (fops *netTunFileOperations) Release() {
-	fops.device.Release()
+func (fops *netTunFileOperations) Release(ctx context.Context) {
+	fops.device.Release(ctx)
 }
 
 // Ioctl implements fs.FileOperations.Ioctl.

pkg/sentry/fs/dirent.go

@@ -325,7 +325,7 @@ func (d *Dirent) SyncAll(ctx context.Context) {
 	for _, w := range d.children {
 		if child := w.Get(); child != nil {
 			child.(*Dirent).SyncAll(ctx)
-			child.DecRef()
+			child.DecRef(ctx)
 		}
 	}
 }
@@ -451,7 +451,7 @@ func (d *Dirent) walk(ctx context.Context, root *Dirent, name string, walkMayUnl
 				// which don't hold a hard reference on their parent (their parent holds a
 				// hard reference on them, and they contain virtually no state). But this is
 				// good house-keeping.
-				child.DecRef()
+				child.DecRef(ctx)
 				return nil, syscall.ENOENT
 			}
 
@@ -468,20 +468,20 @@ func (d *Dirent) walk(ctx context.Context, root *Dirent, name string, walkMayUnl
 			// their pins on the child. Inotify doesn't properly support filesystems that
 			// revalidate dirents (since watches are lost on revalidation), but if we fail
 			// to unpin the watches child will never be GCed.
-			cd.Inode.Watches.Unpin(cd)
+			cd.Inode.Watches.Unpin(ctx, cd)
 
 			// This child needs to be revalidated, fallthrough to unhash it. Make sure
 			// to not leak a reference from Get().
 			//
 			// Note that previous lookups may still have a reference to this stale child;
 			// this can't be helped, but we can ensure that *new* lookups are up-to-date.
-			child.DecRef()
+			child.DecRef(ctx)
 		}
 
 		// Either our weak reference expired or we need to revalidate it. Unhash child first, we're
 		// about to replace it.
 		delete(d.children, name)
-		w.Drop()
+		w.Drop(ctx)
 	}
 
 	// Slow path: load the InodeOperations into memory. Since this is a hot path and the lookup may be
@@ -512,12 +512,12 @@ func (d *Dirent) walk(ctx context.Context, root *Dirent, name string, walkMayUnl
 			// There are active references to the existing child, prefer it to the one we
 			// retrieved from Lookup. Likely the Lookup happened very close to the insertion
 			// of child, so considering one stale over the other is fairly arbitrary.
-			c.DecRef()
+			c.DecRef(ctx)
 
 			// The child that was installed could be negative.
 			if cd.IsNegative() {
 				// If so, don't leak a reference and short circuit.
-				child.DecRef()
+				child.DecRef(ctx)
 				return nil, syscall.ENOENT
 			}
 
@@ -531,7 +531,7 @@ func (d *Dirent) walk(ctx context.Context, root *Dirent, name string, walkMayUnl
 		// we did the Inode.Lookup. Fully drop the weak reference and fallback to using the child
 		// we looked up.
 		delete(d.children, name)
-		w.Drop()
+		w.Drop(ctx)
 	}
 
 	// Give the looked up child a parent. We cannot kick out entries, since we just checked above
@@ -587,7 +587,7 @@ func (d *Dirent) exists(ctx context.Context, root *Dirent, name string) bool {
 		return false
 	}
 	// Child exists.
-	child.DecRef()
+	child.DecRef(ctx)
 	return true
 }
 
@@ -622,7 +622,7 @@ func (d *Dirent) Create(ctx context.Context, root *Dirent, name string, flags Fi
 	}
 	child := file.Dirent
 
-	d.finishCreate(child, name)
+	d.finishCreate(ctx, child, name)
 
 	// Return the reference and the new file. When the last reference to
 	// the file is dropped, file.Dirent may no longer be cached.
@@ -631,7 +631,7 @@ func (d *Dirent) Create(ctx context.Context, root *Dirent, name string, flags Fi
 
 // finishCreate validates the created file, adds it as a child of this dirent,
 // and notifies any watchers.
-func (d *Dirent) finishCreate(child *Dirent, name string) {
+func (d *Dirent) finishCreate(ctx context.Context, child *Dirent, name string) {
 	// Sanity check c, its name must be consistent.
 	if child.name != name {
 		panic(fmt.Sprintf("create from %q to %q returned unexpected name %q", d.name, name, child.name))
@@ -650,14 +650,14 @@ func (d *Dirent) finishCreate(child *Dirent, name string) {
 				panic(fmt.Sprintf("hashed child %q over a positive child", child.name))
 			}
 			// Don't leak a reference.
-			old.DecRef()
+			old.DecRef(ctx)
 
 			// Drop d's reference.
-			old.DecRef()
+			old.DecRef(ctx)
 		}
 
 		// Finally drop the useless weak reference on the floor.
-		w.Drop()
+		w.Drop(ctx)
 	}
 
 	d.Inode.Watches.Notify(name, linux.IN_CREATE, 0)
@@ -686,17 +686,17 @@ func (d *Dirent) genericCreate(ctx context.Context, root *Dirent, name string, c
 				panic(fmt.Sprintf("hashed over a positive child %q", old.(*Dirent).name))
 			}
 			// Don't leak a reference.
-			old.DecRef()
+			old.DecRef(ctx)
 
 			// Drop d's reference.
-			old.DecRef()
+			old.DecRef(ctx)
 		}
 
 		// Unhash the negative Dirent, name needs to exist now.
 		delete(d.children, name)
 
 		// Finally drop the useless weak reference on the floor.
-		w.Drop()
+		w.Drop(ctx)
 	}
 
 	// Execute the create operation.
@@ -756,7 +756,7 @@ func (d *Dirent) Bind(ctx context.Context, root *Dirent, name string, data trans
 		if e != nil {
 			return e
 		}
-		d.finishCreate(childDir, name)
+		d.finishCreate(ctx, childDir, name)
 		return nil
 	})
 	if err == syscall.EEXIST {
@@ -901,7 +901,7 @@ func direntReaddir(ctx context.Context, d *Dirent, it DirIterator, root *Dirent,
 // references to children.
 //
 // Preconditions: d.mu must be held.
-func (d *Dirent) flush() {
+func (d *Dirent) flush(ctx context.Context) {
 	expired := make(map[string]*refs.WeakRef)
 	for n, w := range d.children {
 		// Call flush recursively on each child before removing our
@@ -912,7 +912,7 @@ func (d *Dirent) flush() {
 			if !cd.IsNegative() {
 				// Flush the child.
 				cd.mu.Lock()
-				cd.flush()
+				cd.flush(ctx)
 				cd.mu.Unlock()
 
 				// Allow the file system to drop extra references on child.
@@ -920,13 +920,13 @@ func (d *Dirent) flush() {
 			}
 
 			// Don't leak a reference.
-			child.DecRef()
+			child.DecRef(ctx)
 		}
 		// Check if the child dirent is closed, and mark it as expired if it is.
 		// We must call w.Get() again here, since the child could have been closed
 		// by the calls to flush() and cache.Remove() in the above if-block.
 		if child := w.Get(); child != nil {
-			child.DecRef()
+			child.DecRef(ctx)
 		} else {
 			expired[n] = w
 		}
@@ -935,7 +935,7 @@ func (d *Dirent) flush() {
 	// Remove expired entries.
 	for n, w := range expired {
 		delete(d.children, n)
-		w.Drop()
+		w.Drop(ctx)
 	}
 }
 
@@ -977,7 +977,7 @@ func (d *Dirent) mount(ctx context.Context, inode *Inode) (newChild *Dirent, err
 	if !ok {
 		panic("mount must mount over an existing dirent")
 	}
-	weakRef.Drop()
+	weakRef.Drop(ctx)
 
 	// Note that even though `d` is now hidden, it still holds a reference
 	// to its parent.
@@ -1002,13 +1002,13 @@ func (d *Dirent) unmount(ctx context.Context, replacement *Dirent) error {
 	if !ok {
 		panic("mount must mount over an existing dirent")
 	}
-	weakRef.Drop()
+	weakRef.Drop(ctx)
 
 	// d is not reachable anymore, and hence not mounted anymore.
 	d.mounted = false
 
 	// Drop mount reference.
-	d.DecRef()
+	d.DecRef(ctx)
 	return nil
 }
 
@@ -1029,7 +1029,7 @@ func (d *Dirent) Remove(ctx context.Context, root *Dirent, name string, dirPath
 		// Child does not exist.
 		return err
 	}
-	defer child.DecRef()
+	defer child.DecRef(ctx)
 
 	// Remove cannot remove directories.
 	if IsDir(child.Inode.StableAttr) {
@@ -1055,7 +1055,7 @@ func (d *Dirent) Remove(ctx context.Context, root *Dirent, name string, dirPath
 	atomic.StoreInt32(&child.deleted, 1)
 	if w, ok := d.children[name]; ok {
 		delete(d.children, name)
-		w.Drop()
+		w.Drop(ctx)
 	}
 
 	// Allow the file system to drop extra references on child.
@@ -1067,7 +1067,7 @@ func (d *Dirent) Remove(ctx context.Context, root *Dirent, name string, dirPath
 	// inode may have other links. If this was the last link, the events for the
 	// watch removal will be queued by the inode destructor.
 	child.Inode.Watches.MarkUnlinked()
-	child.Inode.Watches.Unpin(child)
+	child.Inode.Watches.Unpin(ctx, child)
 	d.Inode.Watches.Notify(name, linux.IN_DELETE, 0)
 
 	return nil
@@ -1100,7 +1100,7 @@ func (d *Dirent) RemoveDirectory(ctx context.Context, root *Dirent, name string)
 		// Child does not exist.
 		return err
 	}
-	defer child.DecRef()
+	defer child.DecRef(ctx)
 
 	// RemoveDirectory can only remove directories.
 	if !IsDir(child.Inode.StableAttr) {
@@ -1121,7 +1121,7 @@ func (d *Dirent) RemoveDirectory(ctx context.Context, root *Dirent, name string)
 	atomic.StoreInt32(&child.deleted, 1)
 	if w, ok := d.children[name]; ok {
 		delete(d.children, name)
-		w.Drop()
+		w.Drop(ctx)
 	}
 
 	// Allow the file system to drop extra references on child.
@@ -1130,14 +1130,14 @@ func (d *Dirent) RemoveDirectory(ctx context.Context, root *Dirent, name string)
 	// Finally, let inotify know the child is being unlinked. Drop any extra
 	// refs from inotify to this child dirent.
 	child.Inode.Watches.MarkUnlinked()
-	child.Inode.Watches.Unpin(child)
+	child.Inode.Watches.Unpin(ctx, child)
 	d.Inode.Watches.Notify(name, linux.IN_ISDIR|linux.IN_DELETE, 0)
 
 	return nil
 }
 
 // destroy closes this node and all children.
-func (d *Dirent) destroy() {
+func (d *Dirent) destroy(ctx context.Context) {
 	if d.IsNegative() {
 		// Nothing to tear-down and no parent references to drop, since a negative
 		// Dirent does not take a references on its parent, has no Inode and no children.
@@ -1153,19 +1153,19 @@ func (d *Dirent) destroy() {
 			if c.(*Dirent).IsNegative() {
 				// The parent holds both weak and strong refs in the case of
 				// negative dirents.
-				c.DecRef()
+				c.DecRef(ctx)
 			}
 			// Drop the reference we just acquired in WeakRef.Get.
-			c.DecRef()
+			c.DecRef(ctx)
 		}
-		w.Drop()
+		w.Drop(ctx)
 	}
 	d.children = nil
 
 	allDirents.remove(d)
 
 	// Drop our reference to the Inode.
-	d.Inode.DecRef()
+	d.Inode.DecRef(ctx)
 
 	// Allow the Dirent to be GC'ed after this point, since the Inode may still
 	// be referenced after the Dirent is destroyed (for instance by filesystem
@@ -1175,7 +1175,7 @@ func (d *Dirent) destroy() {
 	// Drop the reference we have on our parent if we took one. renameMu doesn't need to be
 	// held because d can't be reparented without any references to it left.
 	if d.parent != nil {
-		d.parent.DecRef()
+		d.parent.DecRef(ctx)
 	}
 }
 
@@ -1201,14 +1201,14 @@ func (d *Dirent) TryIncRef() bool {
 // DecRef decreases the Dirent's refcount and drops its reference on its mount.
 //
 // DecRef implements RefCounter.DecRef with destructor d.destroy.
-func (d *Dirent) DecRef() {
+func (d *Dirent) DecRef(ctx context.Context) {
 	if d.Inode != nil {
 		// Keep mount around, since DecRef may destroy d.Inode.
 		msrc := d.Inode.MountSource
-		d.DecRefWithDestructor(d.destroy)
+		d.DecRefWithDestructor(ctx, d.destroy)
 		msrc.DecDirentRefs()
 	} else {
-		d.DecRefWithDestructor(d.destroy)
+		d.DecRefWithDestructor(ctx, d.destroy)
 	}
 }
 
@@ -1359,7 +1359,7 @@ func (d *Dirent) MayDelete(ctx context.Context, root *Dirent, name string) error
 	if err != nil {
 		return err
 	}
-	defer victim.DecRef()
+	defer victim.DecRef(ctx)
 
 	return d.mayDelete(ctx, victim)
 }
@@ -1411,7 +1411,7 @@ func Rename(ctx context.Context, root *Dirent, oldParent *Dirent, oldName string
 	if err != nil {
 		return err
 	}
-	defer renamed.DecRef()
+	defer renamed.DecRef(ctx)
 
 	// Check that the renamed dirent is deletable.
 	if err := oldParent.mayDelete(ctx, renamed); err != nil {
@@ -1453,13 +1453,13 @@ func Rename(ctx context.Context, root *Dirent, oldParent *Dirent, oldName string
 
 		// Check that we can delete replaced.
 		if err := newParent.mayDelete(ctx, replaced); err != nil {
-			replaced.DecRef()
+			replaced.DecRef(ctx)
 			return err
 		}
 
 		// Target should not be an ancestor of source.
 		if oldParent.descendantOf(replaced) {
-			replaced.DecRef()
+			replaced.DecRef(ctx)
 
 			// Note that Linux returns EINVAL if the source is an
 			// ancestor of target, but ENOTEMPTY if the target is
@@ -1470,7 +1470,7 @@ func Rename(ctx context.Context, root *Dirent, oldParent *Dirent, oldName string
 
 		// Check that replaced is not a mount point.
 		if replaced.isMountPointLocked() {
-			replaced.DecRef()
+			replaced.DecRef(ctx)
 			return syscall.EBUSY
 		}
 
@@ -1478,11 +1478,11 @@ func Rename(ctx context.Context, root *Dirent, oldParent *Dirent, oldName string
 		oldIsDir := IsDir(renamed.Inode.StableAttr)
 		newIsDir := IsDir(replaced.Inode.StableAttr)
 		if !newIsDir && oldIsDir {
-			replaced.DecRef()
+			replaced.DecRef(ctx)
 			return syscall.ENOTDIR
 		}
 		if !oldIsDir && newIsDir {
-			replaced.DecRef()
+			replaced.DecRef(ctx)
 			return syscall.EISDIR
 		}
 
@@ -1493,13 +1493,13 @@ func Rename(ctx context.Context, root *Dirent, oldParent *Dirent, oldName string
 		// open across renames is currently broken for multiple
 		// reasons, so we flush all references on the replaced node and
 		// its children.
-		replaced.Inode.Watches.Unpin(replaced)
+		replaced.Inode.Watches.Unpin(ctx, replaced)
 		replaced.mu.Lock()
-		replaced.flush()
+		replaced.flush(ctx)
 		replaced.mu.Unlock()
 
 		// Done with replaced.
-		replaced.DecRef()
+		replaced.DecRef(ctx)
 	}
 
 	if err := renamed.Inode.Rename(ctx, oldParent, renamed, newParent, newName, replaced != nil); err != nil {
@@ -1513,14 +1513,14 @@ func Rename(ctx context.Context, root *Dirent, oldParent *Dirent, oldName string
 		// can't destroy oldParent (and try to retake its lock) because
 		// Rename's caller must be holding a reference.
 		newParent.IncRef()
-		oldParent.DecRef()
+		oldParent.DecRef(ctx)
 	}
 	if w, ok := newParent.children[newName]; ok {
-		w.Drop()
+		w.Drop(ctx)
 		delete(newParent.children, newName)
 	}
 	if w, ok := oldParent.children[oldName]; ok {
-		w.Drop()
+		w.Drop(ctx)
 		delete(oldParent.children, oldName)
 	}
 
@@ -1551,7 +1551,7 @@ func Rename(ctx context.Context, root *Dirent, oldParent *Dirent, oldName string
 
 	// Same as replaced.flush above.
 	renamed.mu.Lock()
-	renamed.flush()
+	renamed.flush(ctx)
 	renamed.mu.Unlock()
 
 	return nil

pkg/sentry/fs/dirent_cache.go

@@ -17,6 +17,7 @@ package fs
 import (
 	"fmt"
 
+	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/sync"
 )
 
@@ -101,7 +102,7 @@ func (c *DirentCache) remove(d *Dirent) {
 		panic(fmt.Sprintf("trying to remove %v, which is not in the dirent cache", d))
 	}
 	c.list.Remove(d)
-	d.DecRef()
+	d.DecRef(context.Background())
 	c.currentSize--
 	if c.limit != nil {
 		c.limit.dec()

pkg/sentry/fs/dirent_refs_test.go

@@ -51,7 +51,7 @@ func TestWalkPositive(t *testing.T) {
 		t.Fatalf("child name = %q has a ref count of %d, want %d", d.name, got, 1)
 	}
 
-	d.DecRef()
+	d.DecRef(ctx)
 
 	if got := root.ReadRefs(); got != 1 {
 		t.Fatalf("root has a ref count of %d, want %d", got, 1)
@@ -61,7 +61,7 @@ func TestWalkPositive(t *testing.T) {
 		t.Fatalf("child name = %q has a ref count of %d, want %d", d.name, got, 0)
 	}
 
-	root.flush()
+	root.flush(ctx)
 
 	if got := len(root.children); got != 0 {
 		t.Fatalf("root has %d children, want %d", got, 0)
@@ -114,7 +114,7 @@ func TestWalkNegative(t *testing.T) {
 		t.Fatalf("child has a ref count of %d, want %d", got, 2)
 	}
 
-	child.DecRef()
+	child.DecRef(ctx)
 
 	if got := child.(*Dirent).ReadRefs(); got != 1 {
 		t.Fatalf("child has a ref count of %d, want %d", got, 1)
@@ -124,7 +124,7 @@ func TestWalkNegative(t *testing.T) {
 		t.Fatalf("root has %d children, want %d", got, 1)
 	}
 
-	root.DecRef()
+	root.DecRef(ctx)
 
 	if got := root.ReadRefs(); got != 0 {
 		t.Fatalf("root has a ref count of %d, want %d", got, 0)
@@ -351,9 +351,9 @@ func TestRemoveExtraRefs(t *testing.T) {
 				t.Fatalf("dirent has a ref count of %d, want %d", got, 1)
 			}
 
-			d.DecRef()
+			d.DecRef(ctx)
 
-			test.root.flush()
+			test.root.flush(ctx)
 
 			if got := len(test.root.children); got != 0 {
 				t.Errorf("root has %d children, want %d", got, 0)
@@ -403,8 +403,8 @@ func TestRenameExtraRefs(t *testing.T) {
 				t.Fatalf("Rename got error %v, want nil", err)
 			}
 
-			oldParent.flush()
-			newParent.flush()
+			oldParent.flush(ctx)
+			newParent.flush(ctx)
 
 			// Expect to have only active references.
 			if got := renamed.ReadRefs(); got != 1 {

pkg/sentry/fs/dirent_state.go

@@ -18,6 +18,7 @@ import (
 	"fmt"
 	"sync/atomic"
 
+	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/refs"
 )
 
@@ -48,7 +49,7 @@ func (d *Dirent) saveChildren() map[string]*Dirent {
 	for name, w := range d.children {
 		if rc := w.Get(); rc != nil {
 			// Drop the reference count obtain in w.Get()
-			rc.DecRef()
+			rc.DecRef(context.Background())
 
 			cd := rc.(*Dirent)
 			if cd.IsNegative() {

pkg/sentry/fs/fdpipe/pipe.go

@@ -115,7 +115,7 @@ func (p *pipeOperations) Readiness(mask waiter.EventMask) (eventMask waiter.Even
 }
 
 // Release implements fs.FileOperations.Release.
-func (p *pipeOperations) Release() {
+func (p *pipeOperations) Release(context.Context) {
 	fdnotifier.RemoveFD(int32(p.file.FD()))
 	p.file.Close()
 	p.file = nil

pkg/sentry/fs/fdpipe/pipe_opener_test.go

@@ -182,7 +182,7 @@ func TestTryOpen(t *testing.T) {
 				// Cleanup the state of the pipe, and remove the fd from the
 				// fdnotifier.  Sadly this needed to maintain the correctness
 				// of other tests because the fdnotifier is global.
-				pipeOps.Release()
+				pipeOps.Release(ctx)
 			}
 			continue
 		}
@@ -191,7 +191,7 @@ func TestTryOpen(t *testing.T) {
 		}
 		if pipeOps != nil {
 			// Same as above.
-			pipeOps.Release()
+			pipeOps.Release(ctx)
 		}
 	}
 }
@@ -279,7 +279,7 @@ func TestPipeOpenUnblocksEventually(t *testing.T) {
 		pipeOps, err := Open(ctx, opener, flags)
 		if pipeOps != nil {
 			// Same as TestTryOpen.
-			pipeOps.Release()
+			pipeOps.Release(ctx)
 		}
 
 		// Check that the partner opened the file successfully.
@@ -325,7 +325,7 @@ func TestCopiedReadAheadBuffer(t *testing.T) {
 	ctx := contexttest.Context(t)
 	pipeOps, err := pipeOpenState.TryOpen(ctx, opener, fs.FileFlags{Read: true})
 	if pipeOps != nil {
-		pipeOps.Release()
+		pipeOps.Release(ctx)
 		t.Fatalf("open(%s, %o) got file, want nil", name, syscall.O_RDONLY)
 	}
 	if err != syserror.ErrWouldBlock {
@@ -351,7 +351,7 @@ func TestCopiedReadAheadBuffer(t *testing.T) {
 	if pipeOps == nil {
 		t.Fatalf("open(%s, %o) got nil file, want not nil", name, syscall.O_RDONLY)
 	}
-	defer pipeOps.Release()
+	defer pipeOps.Release(ctx)
 
 	if err != nil {
 		t.Fatalf("open(%s, %o) got error %v, want nil", name, syscall.O_RDONLY, err)
@@ -471,14 +471,14 @@ func TestPipeHangup(t *testing.T) {
 		f := <-fdchan
 		if f < 0 {
 			t.Errorf("%s: partner routine got fd %d, want > 0", test.desc, f)
-			pipeOps.Release()
+			pipeOps.Release(ctx)
 			continue
 		}
 
 		if test.hangupSelf {
 			// Hangup self and assert that our partner got the expected hangup
 			// error.
-			pipeOps.Release()
+			pipeOps.Release(ctx)
 
 			if test.flags.Read {
 				// Partner is writer.
@@ -490,7 +490,7 @@ func TestPipeHangup(t *testing.T) {
 		} else {
 			// Hangup our partner and expect us to get the hangup error.
 			syscall.Close(f)
-			defer pipeOps.Release()
+			defer pipeOps.Release(ctx)
 
 			if test.flags.Read {
 				assertReaderHungup(t, test.desc, pipeOps.(*pipeOperations).file)