From 084d1ea422f14a98f3d72d4b917a21b0a620b6e4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Llu=C3=ADs=20Batlle=20i=20Rossell?= <viric@viric.name>
Date: Tue, 23 Feb 2021 22:25:30 +0100
Subject: [PATCH] Improving error handling

Following review requests
---
 unix/syscall_linux.go      |  3 +++
 unix/syscall_linux_test.go | 21 ++++++++++-----------
 2 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/unix/syscall_linux.go b/unix/syscall_linux.go
index 775f74d5..fc494fd4 100644
--- a/unix/syscall_linux.go
+++ b/unix/syscall_linux.go
@@ -185,8 +185,11 @@ func IoctlFileDedupeRange(srcFd int, value *FileDedupeRange) error {
 		rawinfo := (*RawFileDedupeRangeInfo)(unsafe.Pointer(
 			uintptr(unsafe.Pointer(&buf[0])) + uintptr(SizeofRawFileDedupeRange) +
 				uintptr(i*SizeofRawFileDedupeRangeInfo)))
+		value.Info[i].Dest_fd = rawinfo.Dest_fd
+		value.Info[i].Dest_offset = rawinfo.Dest_offset
 		value.Info[i].Bytes_deduped = rawinfo.Bytes_deduped
 		value.Info[i].Status = rawinfo.Status
+		value.Info[i].Reserved = rawinfo.Reserved
 	}
 
 	return err
diff --git a/unix/syscall_linux_test.go b/unix/syscall_linux_test.go
index e3b224ee..5af742eb 100644
--- a/unix/syscall_linux_test.go
+++ b/unix/syscall_linux_test.go
@@ -798,8 +798,9 @@ func TestOpenat2(t *testing.T) {
 
 func TestFideduperange(t *testing.T) {
 	if runtime.GOOS == "android" {
-		// In android amd64 it returned ENOTTY
-		t.Skip("FIDEDUPERANGE ioctl is not available on android, skipping test")
+		// The ioctl in the build robot android-amd64 returned ENOTTY,
+		// an error not documented for that syscall.
+		t.Skip("FIDEDUPERANGE ioctl doesn't work the test android, skipping test")
 	}
 
 	f1, err := ioutil.TempFile("", t.Name())
@@ -809,8 +810,11 @@ func TestFideduperange(t *testing.T) {
 	defer f1.Close()
 	defer os.Remove(f1.Name())
 
+	// Test deduplication with two blocks of zeros
+	data := make([]byte, 4096)
+
 	for i := 0; i < 2; i += 1 {
-		_, err = f1.Write(make([]byte, 4096))
+		_, err = f1.Write(data)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -824,8 +828,6 @@ func TestFideduperange(t *testing.T) {
 	defer os.Remove(f2.Name())
 
 	for i := 0; i < 2; i += 1 {
-		data := make([]byte, 4096)
-
 		// Make the 2nd block different
 		if i == 1 {
 			data[1] = 1
@@ -852,12 +854,9 @@ func TestFideduperange(t *testing.T) {
 		}}
 
 	err = unix.IoctlFileDedupeRange(int(f1.Fd()), &dedupe)
-
-	if err != nil {
-		if err == unix.EOPNOTSUPP {
-			// We can't test if the fs doesn't support deduplication
-			t.Skipf("skipping test, %v", err)
-		}
+	if err == unix.EOPNOTSUPP || err == unix.EINVAL {
+		t.Skip("deduplication not supported on this filesystem")
+	} else if err != nil {
 		t.Fatal(err)
 	}