CachingInodeOperations was over-dirtying cached attributes

Dirty should be set only when the attribute is changed in the cache
only. Instances where the change was also sent to the backing file
doesn't need to dirty the attribute.

Also remove size update during WriteOut as writing dirty page would
naturaly grow the file if needed.

RELNOTES: relnotes is needed for the parent CL.
PiperOrigin-RevId: 232068978
Change-Id: I00ba54693a2c7adc06efa9e030faf8f2e8e7f188

1 files changed, 11 insertions, 28 deletions

diff --git a/pkg/sentry/fs/fsutil/inode_cached_test.go b/pkg/sentry/fs/fsutil/inode_cached_test.go
index 9c9391511..2a8a1639c 100644
--- a/pkg/sentry/fs/fsutil/inode_cached_test.go
+++ b/pkg/sentry/fs/fsutil/inode_cached_test.go
@@ -17,7 +17,6 @@ package fsutil
 import (
 	"bytes"
 	"io"
-	"reflect"
 	"testing"
 
 	"gvisor.googlesource.com/gvisor/pkg/sentry/context"
@@ -66,9 +65,6 @@ func TestSetPermissions(t *testing.T) {
 	}
 
 	// Did permissions change?
-	if !iops.dirtyAttr.Perms {
-		t.Fatalf("got perms not dirty, want dirty")
-	}
 	if iops.attr.Perms != perms {
 		t.Fatalf("got perms +%v, want +%v", iops.attr.Perms, perms)
 	}
@@ -85,9 +81,9 @@ func TestSetPermissions(t *testing.T) {
 func TestSetTimestamps(t *testing.T) {
 	ctx := contexttest.Context(t)
 	for _, test := range []struct {
-		desc      string
-		ts        fs.TimeSpec
-		wantDirty fs.AttrMask
+		desc        string
+		ts          fs.TimeSpec
+		wantChanged fs.AttrMask
 	}{
 		{
 			desc: "noop",
@@ -95,7 +91,7 @@ func TestSetTimestamps(t *testing.T) {
 				ATimeOmit: true,
 				MTimeOmit: true,
 			},
-			wantDirty: fs.AttrMask{},
+			wantChanged: fs.AttrMask{},
 		},
 		{
 			desc: "access time only",
@@ -103,9 +99,8 @@ func TestSetTimestamps(t *testing.T) {
 				ATime:     ktime.NowFromContext(ctx),
 				MTimeOmit: true,
 			},
-			wantDirty: fs.AttrMask{
-				AccessTime:       true,
-				StatusChangeTime: true,
+			wantChanged: fs.AttrMask{
+				AccessTime: true,
 			},
 		},
 		{
@@ -114,9 +109,8 @@ func TestSetTimestamps(t *testing.T) {
 				ATimeOmit: true,
 				MTime:     ktime.NowFromContext(ctx),
 			},
-			wantDirty: fs.AttrMask{
+			wantChanged: fs.AttrMask{
 				ModificationTime: true,
-				StatusChangeTime: true,
 			},
 		},
 		{
@@ -125,10 +119,9 @@ func TestSetTimestamps(t *testing.T) {
 				ATime: ktime.NowFromContext(ctx),
 				MTime: ktime.NowFromContext(ctx),
 			},
-			wantDirty: fs.AttrMask{
+			wantChanged: fs.AttrMask{
 				AccessTime:       true,
 				ModificationTime: true,
-				StatusChangeTime: true,
 			},
 		},
 		{
@@ -137,10 +130,9 @@ func TestSetTimestamps(t *testing.T) {
 				ATimeSetSystemTime: true,
 				MTimeSetSystemTime: true,
 			},
-			wantDirty: fs.AttrMask{
+			wantChanged: fs.AttrMask{
 				AccessTime:       true,
 				ModificationTime: true,
-				StatusChangeTime: true,
 			},
 		},
 	} {
@@ -159,10 +151,7 @@ func TestSetTimestamps(t *testing.T) {
 			if err := iops.SetTimestamps(ctx, nil, test.ts); err != nil {
 				t.Fatalf("SetTimestamps got error %v, want nil", err)
 			}
-			if !reflect.DeepEqual(iops.dirtyAttr, test.wantDirty) {
-				t.Fatalf("dirty got %+v, want %+v", iops.dirtyAttr, test.wantDirty)
-			}
-			if iops.dirtyAttr.AccessTime {
+			if test.wantChanged.AccessTime {
 				if !iops.attr.AccessTime.After(uattr.AccessTime) {
 					t.Fatalf("diritied access time did not advance, want %v > %v", iops.attr.AccessTime, uattr.AccessTime)
 				}
@@ -173,7 +162,7 @@ func TestSetTimestamps(t *testing.T) {
 					t.Fatalf("dirtied status change time did not advance")
 				}
 			}
-			if iops.dirtyAttr.ModificationTime {
+			if test.wantChanged.ModificationTime {
 				if !iops.attr.ModificationTime.After(uattr.ModificationTime) {
 					t.Fatalf("diritied modification time did not advance")
 				}
@@ -200,16 +189,10 @@ func TestTruncate(t *testing.T) {
 	if err := iops.Truncate(ctx, nil, uattr.Size); err != nil {
 		t.Fatalf("Truncate got error %v, want nil", err)
 	}
-	if iops.dirtyAttr.Size {
-		t.Fatalf("Truncate caused size to be dirtied")
-	}
 	var size int64 = 4096
 	if err := iops.Truncate(ctx, nil, size); err != nil {
 		t.Fatalf("Truncate got error %v, want nil", err)
 	}
-	if !iops.dirtyAttr.Size {
-		t.Fatalf("Truncate caused size to not be dirtied")
-	}
 	if iops.attr.Size != size {
 		t.Fatalf("Truncate got %d, want %d", iops.attr.Size, size)
 	}