4 files changed, 20 insertions, 8 deletions
diff --git a/pkg/sentry/fs/file.go b/pkg/sentry/fs/file.go
index c0a6e884b..a2f966cb6 100644
--- a/pkg/sentry/fs/file.go
+++ b/pkg/sentry/fs/file.go
@@ -555,6 +555,10 @@ type lockedWriter struct {
 	//
 	// This applies only to Write, not WriteAt.
 	Offset int64
+
+	// Err contains the first error encountered while copying. This is
+	// useful to determine whether Writer or Reader failed during io.Copy.
+	Err error
 }
 
 // Write implements io.Writer.Write.
@@ -590,5 +594,8 @@ func (w *lockedWriter) WriteAt(buf []byte, offset int64) (int, error) {
 			break
 		}
 	}
+	if w.Err == nil {
+		w.Err = err
+	}
 	return written, err
 }
diff --git a/pkg/sentry/fs/fsutil/BUILD b/pkg/sentry/fs/fsutil/BUILD
index b2e8d9c77..9ca695a95 100644
--- a/pkg/sentry/fs/fsutil/BUILD
+++ b/pkg/sentry/fs/fsutil/BUILD
@@ -53,7 +53,7 @@ go_template_instance(
         "Key": "uint64",
         "Range": "memmap.MappableRange",
         "Value": "uint64",
-        "Functions": "fileRangeSetFunctions",
+        "Functions": "FileRangeSetFunctions",
     },
 )
 
diff --git a/pkg/sentry/fs/fsutil/file_range_set.go b/pkg/sentry/fs/fsutil/file_range_set.go
index 0a5466b0a..f52d712e3 100644
--- a/pkg/sentry/fs/fsutil/file_range_set.go
+++ b/pkg/sentry/fs/fsutil/file_range_set.go
@@ -34,25 +34,25 @@ import (
 //
 // type FileRangeSet <generated by go_generics>
 
-// fileRangeSetFunctions implements segment.Functions for FileRangeSet.
-type fileRangeSetFunctions struct{}
+// FileRangeSetFunctions implements segment.Functions for FileRangeSet.
+type FileRangeSetFunctions struct{}
 
 // MinKey implements segment.Functions.MinKey.
-func (fileRangeSetFunctions) MinKey() uint64 {
+func (FileRangeSetFunctions) MinKey() uint64 {
 	return 0
 }
 
 // MaxKey implements segment.Functions.MaxKey.
-func (fileRangeSetFunctions) MaxKey() uint64 {
+func (FileRangeSetFunctions) MaxKey() uint64 {
 	return math.MaxUint64
 }
 
 // ClearValue implements segment.Functions.ClearValue.
-func (fileRangeSetFunctions) ClearValue(_ *uint64) {
+func (FileRangeSetFunctions) ClearValue(_ *uint64) {
 }
 
 // Merge implements segment.Functions.Merge.
-func (fileRangeSetFunctions) Merge(mr1 memmap.MappableRange, frstart1 uint64, _ memmap.MappableRange, frstart2 uint64) (uint64, bool) {
+func (FileRangeSetFunctions) Merge(mr1 memmap.MappableRange, frstart1 uint64, _ memmap.MappableRange, frstart2 uint64) (uint64, bool) {
 	if frstart1+mr1.Length() != frstart2 {
 		return 0, false
 	}
@@ -60,7 +60,7 @@ func (fileRangeSetFunctions) Merge(mr1 memmap.MappableRange, frstart1 uint64, _
 }
 
 // Split implements segment.Functions.Split.
-func (fileRangeSetFunctions) Split(mr memmap.MappableRange, frstart uint64, split uint64) (uint64, uint64) {
+func (FileRangeSetFunctions) Split(mr memmap.MappableRange, frstart uint64, split uint64) (uint64, uint64) {
 	return frstart, frstart + (split - mr.Start)
 }
 
diff --git a/pkg/sentry/fs/splice.go b/pkg/sentry/fs/splice.go
index 311798811..389c330a0 100644
--- a/pkg/sentry/fs/splice.go
+++ b/pkg/sentry/fs/splice.go
@@ -167,6 +167,11 @@ func Splice(ctx context.Context, dst *File, src *File, opts SpliceOpts) (int64,
 		if !srcPipe && !opts.SrcOffset {
 			atomic.StoreInt64(&src.offset, src.offset+n)
 		}
+
+		// Don't report any errors if we have some progress without data loss.
+		if w.Err == nil {
+			err = nil
+		}
 	}
 
 	// Drop locks.