unix: fix and test the FIDEDUPERANGE Linux ioctl
The previous implementation didn't match the ioctl spec.
Fixes golang/go#43678
Change-Id: Ia1c292c2dbd4913fb1d7e8331d9f18e23169d64a
GitHub-Last-Rev: 5331c424ef5dd0384afda9effbb76afd7705ecfd
GitHub-Pull-Request: golang/sys#97
Reviewed-on: https://go-review.googlesource.com/c/sys/+/284352
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Trust: Ian Lance Taylor <iant@golang.org>
diff --git a/unix/linux/types.go b/unix/linux/types.go
index ab2be60..ef138cf 100644
--- a/unix/linux/types.go
+++ b/unix/linux/types.go
@@ -474,7 +474,16 @@
type FileCloneRange C.struct_file_clone_range
-type FileDedupeRange C.struct_file_dedupe_range
+type RawFileDedupeRange C.struct_file_dedupe_range
+
+type RawFileDedupeRangeInfo C.struct_file_dedupe_range_info
+
+const (
+ SizeofRawFileDedupeRange = C.sizeof_struct_file_dedupe_range
+ SizeofRawFileDedupeRangeInfo = C.sizeof_struct_file_dedupe_range_info
+ FILE_DEDUPE_RANGE_SAME = C.FILE_DEDUPE_RANGE_SAME
+ FILE_DEDUPE_RANGE_DIFFERS = C.FILE_DEDUPE_RANGE_DIFFERS
+)
// Filesystem Encryption
diff --git a/unix/syscall_linux.go b/unix/syscall_linux.go
index ad49b27..0a48548 100644
--- a/unix/syscall_linux.go
+++ b/unix/syscall_linux.go
@@ -137,12 +137,61 @@
return ioctl(destFd, FICLONE, uintptr(srcFd))
}
+type FileDedupeRange struct {
+ Src_offset uint64
+ Src_length uint64
+ Reserved1 uint16
+ Reserved2 uint32
+ Info []FileDedupeRangeInfo
+}
+
+type FileDedupeRangeInfo struct {
+ Dest_fd int64
+ Dest_offset uint64
+ Bytes_deduped uint64
+ Status int32
+ Reserved uint32
+}
+
// IoctlFileDedupeRange performs an FIDEDUPERANGE ioctl operation to share the
-// range of data conveyed in value with the file associated with the file
-// descriptor destFd. See the ioctl_fideduperange(2) man page for details.
-func IoctlFileDedupeRange(destFd int, value *FileDedupeRange) error {
- err := ioctl(destFd, FIDEDUPERANGE, uintptr(unsafe.Pointer(value)))
- runtime.KeepAlive(value)
+// range of data conveyed in value from the file associated with the file
+// descriptor srcFd to the value.Info destinations. See the
+// ioctl_fideduperange(2) man page for details.
+func IoctlFileDedupeRange(srcFd int, value *FileDedupeRange) error {
+ buf := make([]byte, SizeofRawFileDedupeRange+
+ len(value.Info)*SizeofRawFileDedupeRangeInfo)
+ rawrange := (*RawFileDedupeRange)(unsafe.Pointer(&buf[0]))
+ rawrange.Src_offset = value.Src_offset
+ rawrange.Src_length = value.Src_length
+ rawrange.Dest_count = uint16(len(value.Info))
+ rawrange.Reserved1 = value.Reserved1
+ rawrange.Reserved2 = value.Reserved2
+
+ for i := range value.Info {
+ rawinfo := (*RawFileDedupeRangeInfo)(unsafe.Pointer(
+ uintptr(unsafe.Pointer(&buf[0])) + uintptr(SizeofRawFileDedupeRange) +
+ uintptr(i*SizeofRawFileDedupeRangeInfo)))
+ rawinfo.Dest_fd = value.Info[i].Dest_fd
+ rawinfo.Dest_offset = value.Info[i].Dest_offset
+ rawinfo.Bytes_deduped = value.Info[i].Bytes_deduped
+ rawinfo.Status = value.Info[i].Status
+ rawinfo.Reserved = value.Info[i].Reserved
+ }
+
+ err := ioctl(srcFd, FIDEDUPERANGE, uintptr(unsafe.Pointer(&buf[0])))
+
+ // Output
+ for i := range value.Info {
+ 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 db1a960..699e56f 100644
--- a/unix/syscall_linux_test.go
+++ b/unix/syscall_linux_test.go
@@ -796,3 +796,94 @@
t.Errorf("Openat2 should fail with EXDEV, got %v", err)
}
}
+
+func TestFideduperange(t *testing.T) {
+ if runtime.GOOS == "android" {
+ // The ioctl in the build robot android-amd64 returned ENOTTY,
+ // an error not documented for that syscall.
+ t.Skip("FIDEDUPERANGE ioctl doesn't work on android, skipping test")
+ }
+
+ f1, err := ioutil.TempFile("", t.Name())
+ if err != nil {
+ t.Fatal(err)
+ }
+ 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(data)
+ if err != nil {
+ t.Fatal(err)
+ }
+ }
+
+ f2, err := ioutil.TempFile("", t.Name())
+ if err != nil {
+ t.Fatal(err)
+ }
+ defer f2.Close()
+ defer os.Remove(f2.Name())
+
+ for i := 0; i < 2; i += 1 {
+ // Make the 2nd block different
+ if i == 1 {
+ data[1] = 1
+ }
+
+ _, err = f2.Write(data)
+ if err != nil {
+ t.Fatal(err)
+ }
+ }
+
+ dedupe := unix.FileDedupeRange{
+ Src_offset: uint64(0),
+ Src_length: uint64(4096),
+ Info: []unix.FileDedupeRangeInfo{
+ unix.FileDedupeRangeInfo{
+ Dest_fd: int64(f2.Fd()),
+ Dest_offset: uint64(0),
+ },
+ unix.FileDedupeRangeInfo{
+ Dest_fd: int64(f2.Fd()),
+ Dest_offset: uint64(4096),
+ },
+ }}
+
+ err = unix.IoctlFileDedupeRange(int(f1.Fd()), &dedupe)
+ if err == unix.EOPNOTSUPP || err == unix.EINVAL {
+ t.Skip("deduplication not supported on this filesystem")
+ } else if err != nil {
+ t.Fatal(err)
+ }
+
+ // The first Info should be equal
+ if dedupe.Info[0].Status < 0 {
+ // We expect status to be a negated errno
+ t.Errorf("Unexpected error in FileDedupeRange: %s",
+ unix.ErrnoName(unix.Errno(-dedupe.Info[0].Status)))
+ } else if dedupe.Info[0].Status == unix.FILE_DEDUPE_RANGE_DIFFERS {
+ t.Errorf("Unexpected different bytes in FileDedupeRange")
+ }
+ if dedupe.Info[0].Bytes_deduped != 4096 {
+ t.Errorf("Unexpected amount of bytes deduped %v != %v",
+ dedupe.Info[0].Bytes_deduped, 4096)
+ }
+
+ // The second Info should be different
+ if dedupe.Info[1].Status < 0 {
+ // We expect status to be a negated errno
+ t.Errorf("Unexpected error in FileDedupeRange: %s",
+ unix.ErrnoName(unix.Errno(-dedupe.Info[1].Status)))
+ } else if dedupe.Info[1].Status == unix.FILE_DEDUPE_RANGE_SAME {
+ t.Errorf("Unexpected equal bytes in FileDedupeRange")
+ }
+ if dedupe.Info[1].Bytes_deduped != 0 {
+ t.Errorf("Unexpected amount of bytes deduped %v != %v",
+ dedupe.Info[1].Bytes_deduped, 0)
+ }
+}
diff --git a/unix/ztypes_linux.go b/unix/ztypes_linux.go
index 3f922db..d3a1871 100644
--- a/unix/ztypes_linux.go
+++ b/unix/ztypes_linux.go
@@ -84,7 +84,7 @@
Dest_offset uint64
}
-type FileDedupeRange struct {
+type RawFileDedupeRange struct {
Src_offset uint64
Src_length uint64
Dest_count uint16
@@ -92,6 +92,21 @@
Reserved2 uint32
}
+type RawFileDedupeRangeInfo struct {
+ Dest_fd int64
+ Dest_offset uint64
+ Bytes_deduped uint64
+ Status int32
+ Reserved uint32
+}
+
+const (
+ SizeofRawFileDedupeRange = 0x18
+ SizeofRawFileDedupeRangeInfo = 0x20
+ FILE_DEDUPE_RANGE_SAME = 0x0
+ FILE_DEDUPE_RANGE_DIFFERS = 0x1
+)
+
type FscryptPolicy struct {
Version uint8
Contents_encryption_mode uint8
