Allow vfs.IterDirentsCallback.Handle() to return an error.

This is easier than storing errors from e.g. CopyOut in the callback.

PiperOrigin-RevId: 295230021

9 files changed, 37 insertions, 37 deletions

diff --git a/pkg/sentry/fsimpl/ext/directory.go b/pkg/sentry/fsimpl/ext/directory.go
index ebb72b75e..bd6ede995 100644
--- a/pkg/sentry/fsimpl/ext/directory.go
+++ b/pkg/sentry/fsimpl/ext/directory.go
@@ -188,14 +188,14 @@ func (fd *directoryFD) IterDirents(ctx context.Context, cb vfs.IterDirentsCallba
 				childType = fs.ToInodeType(childInode.diskInode.Mode().FileType())
 			}
 
-			if !cb.Handle(vfs.Dirent{
+			if err := cb.Handle(vfs.Dirent{
 				Name:    child.diskDirent.FileName(),
 				Type:    fs.ToDirentType(childType),
 				Ino:     uint64(child.diskDirent.Inode()),
 				NextOff: fd.off + 1,
-			}) {
+			}); err != nil {
 				dir.childList.InsertBefore(child, fd.iter)
-				return nil
+				return err
 			}
 			fd.off++
 		}
diff --git a/pkg/sentry/fsimpl/ext/ext_test.go b/pkg/sentry/fsimpl/ext/ext_test.go
index ef6127f3c..29bb73765 100644
--- a/pkg/sentry/fsimpl/ext/ext_test.go
+++ b/pkg/sentry/fsimpl/ext/ext_test.go
@@ -499,9 +499,9 @@ func newIterDirentCb() *iterDirentsCb {
 }
 
 // Handle implements vfs.IterDirentsCallback.Handle.
-func (cb *iterDirentsCb) Handle(dirent vfs.Dirent) bool {
+func (cb *iterDirentsCb) Handle(dirent vfs.Dirent) error {
 	cb.dirents = append(cb.dirents, dirent)
-	return true
+	return nil
 }
 
 // TestIterDirents tests the FileDescriptionImpl.IterDirents functionality.
diff --git a/pkg/sentry/fsimpl/gofer/directory.go b/pkg/sentry/fsimpl/gofer/directory.go
index 6d4ebc2bf..5dbfc6250 100644
--- a/pkg/sentry/fsimpl/gofer/directory.go
+++ b/pkg/sentry/fsimpl/gofer/directory.go
@@ -65,8 +65,8 @@ func (fd *directoryFD) IterDirents(ctx context.Context, cb vfs.IterDirentsCallba
 	}
 
 	for fd.off < int64(len(fd.dirents)) {
-		if !cb.Handle(fd.dirents[fd.off]) {
-			return nil
+		if err := cb.Handle(fd.dirents[fd.off]); err != nil {
+			return err
 		}
 		fd.off++
 	}
diff --git a/pkg/sentry/fsimpl/kernfs/fd_impl_util.go b/pkg/sentry/fsimpl/kernfs/fd_impl_util.go
index eda781155..5650512e0 100644
--- a/pkg/sentry/fsimpl/kernfs/fd_impl_util.go
+++ b/pkg/sentry/fsimpl/kernfs/fd_impl_util.go
@@ -116,8 +116,8 @@ func (fd *GenericDirectoryFD) IterDirents(ctx context.Context, cb vfs.IterDirent
 			Ino:     stat.Ino,
 			NextOff: 1,
 		}
-		if !cb.Handle(dirent) {
-			return nil
+		if err := cb.Handle(dirent); err != nil {
+			return err
 		}
 		fd.off++
 	}
@@ -132,8 +132,8 @@ func (fd *GenericDirectoryFD) IterDirents(ctx context.Context, cb vfs.IterDirent
 			Ino:     stat.Ino,
 			NextOff: 2,
 		}
-		if !cb.Handle(dirent) {
-			return nil
+		if err := cb.Handle(dirent); err != nil {
+			return err
 		}
 		fd.off++
 	}
@@ -153,8 +153,8 @@ func (fd *GenericDirectoryFD) IterDirents(ctx context.Context, cb vfs.IterDirent
 			Ino:     stat.Ino,
 			NextOff: fd.off + 1,
 		}
-		if !cb.Handle(dirent) {
-			return nil
+		if err := cb.Handle(dirent); err != nil {
+			return err
 		}
 		fd.off++
 	}
diff --git a/pkg/sentry/fsimpl/proc/subtasks.go b/pkg/sentry/fsimpl/proc/subtasks.go
index 102af0e93..f3f4e49b4 100644
--- a/pkg/sentry/fsimpl/proc/subtasks.go
+++ b/pkg/sentry/fsimpl/proc/subtasks.go
@@ -105,8 +105,8 @@ func (i *subtasksInode) IterDirents(ctx context.Context, cb vfs.IterDirentsCallb
 			Ino:     i.inoGen.NextIno(),
 			NextOff: offset + 1,
 		}
-		if !cb.Handle(dirent) {
-			return offset, nil
+		if err := cb.Handle(dirent); err != nil {
+			return offset, err
 		}
 		offset++
 	}
diff --git a/pkg/sentry/fsimpl/proc/tasks.go b/pkg/sentry/fsimpl/proc/tasks.go
index ebe21630c..ce08a7d53 100644
--- a/pkg/sentry/fsimpl/proc/tasks.go
+++ b/pkg/sentry/fsimpl/proc/tasks.go
@@ -151,8 +151,8 @@ func (i *tasksInode) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback
 			Ino:     i.inoGen.NextIno(),
 			NextOff: offset + 1,
 		}
-		if !cb.Handle(dirent) {
-			return offset, nil
+		if err := cb.Handle(dirent); err != nil {
+			return offset, err
 		}
 		offset++
 	}
@@ -163,8 +163,8 @@ func (i *tasksInode) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback
 			Ino:     i.inoGen.NextIno(),
 			NextOff: offset + 1,
 		}
-		if !cb.Handle(dirent) {
-			return offset, nil
+		if err := cb.Handle(dirent); err != nil {
+			return offset, err
 		}
 		offset++
 	}
@@ -196,8 +196,8 @@ func (i *tasksInode) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback
 			Ino:     i.inoGen.NextIno(),
 			NextOff: FIRST_PROCESS_ENTRY + 2 + int64(tid) + 1,
 		}
-		if !cb.Handle(dirent) {
-			return offset, nil
+		if err := cb.Handle(dirent); err != nil {
+			return offset, err
 		}
 		offset++
 	}
diff --git a/pkg/sentry/fsimpl/testutil/testutil.go b/pkg/sentry/fsimpl/testutil/testutil.go
index b97e3534a..e16808c63 100644
--- a/pkg/sentry/fsimpl/testutil/testutil.go
+++ b/pkg/sentry/fsimpl/testutil/testutil.go
@@ -226,7 +226,7 @@ func (d *DirentCollector) SkipDotsChecks(value bool) {
 }
 
 // Handle implements vfs.IterDirentsCallback.Handle.
-func (d *DirentCollector) Handle(dirent vfs.Dirent) bool {
+func (d *DirentCollector) Handle(dirent vfs.Dirent) error {
 	d.mu.Lock()
 	if d.dirents == nil {
 		d.dirents = make(map[string]*vfs.Dirent)
@@ -234,7 +234,7 @@ func (d *DirentCollector) Handle(dirent vfs.Dirent) bool {
 	d.order = append(d.order, &dirent)
 	d.dirents[dirent.Name] = &dirent
 	d.mu.Unlock()
-	return true
+	return nil
 }
 
 // Count returns the number of dirents currently in the collector.
diff --git a/pkg/sentry/fsimpl/tmpfs/directory.go b/pkg/sentry/fsimpl/tmpfs/directory.go
index dc0d27cf9..b4380af38 100644
--- a/pkg/sentry/fsimpl/tmpfs/directory.go
+++ b/pkg/sentry/fsimpl/tmpfs/directory.go
@@ -74,25 +74,25 @@ func (fd *directoryFD) IterDirents(ctx context.Context, cb vfs.IterDirentsCallba
 	defer fs.mu.Unlock()
 
 	if fd.off == 0 {
-		if !cb.Handle(vfs.Dirent{
+		if err := cb.Handle(vfs.Dirent{
 			Name:    ".",
 			Type:    linux.DT_DIR,
 			Ino:     vfsd.Impl().(*dentry).inode.ino,
 			NextOff: 1,
-		}) {
-			return nil
+		}); err != nil {
+			return err
 		}
 		fd.off++
 	}
 	if fd.off == 1 {
 		parentInode := vfsd.ParentOrSelf().Impl().(*dentry).inode
-		if !cb.Handle(vfs.Dirent{
+		if err := cb.Handle(vfs.Dirent{
 			Name:    "..",
 			Type:    parentInode.direntType(),
 			Ino:     parentInode.ino,
 			NextOff: 2,
-		}) {
-			return nil
+		}); err != nil {
+			return err
 		}
 		fd.off++
 	}
@@ -111,14 +111,14 @@ func (fd *directoryFD) IterDirents(ctx context.Context, cb vfs.IterDirentsCallba
 	for child != nil {
 		// Skip other directoryFD iterators.
 		if child.inode != nil {
-			if !cb.Handle(vfs.Dirent{
+			if err := cb.Handle(vfs.Dirent{
 				Name:    child.vfsd.Name(),
 				Type:    child.inode.direntType(),
 				Ino:     child.inode.ino,
 				NextOff: fd.off + 1,
-			}) {
+			}); err != nil {
 				dir.childList.InsertBefore(child, fd.iter)
-				return nil
+				return err
 			}
 			fd.off++
 		}
diff --git a/pkg/sentry/vfs/file_description.go b/pkg/sentry/vfs/file_description.go
index 5bac660c7..9a1ad630c 100644
--- a/pkg/sentry/vfs/file_description.go
+++ b/pkg/sentry/vfs/file_description.go
@@ -435,11 +435,11 @@ type Dirent struct {
 
 // IterDirentsCallback receives Dirents from FileDescriptionImpl.IterDirents.
 type IterDirentsCallback interface {
-	// Handle handles the given iterated Dirent. It returns true if iteration
-	// should continue, and false if FileDescriptionImpl.IterDirents should
-	// terminate now and restart with the same Dirent the next time it is
-	// called.
-	Handle(dirent Dirent) bool
+	// Handle handles the given iterated Dirent. If Handle returns a non-nil
+	// error, FileDescriptionImpl.IterDirents must stop iteration and return
+	// the error; the next call to FileDescriptionImpl.IterDirents should
+	// restart with the same Dirent.
+	Handle(dirent Dirent) error
 }
 
 // OnClose is called when a file descriptor representing the FileDescription is