Merge pull request containerd#24 from zhsj/fix-mipsle

fix slice size overflow on mipsle

README.md

@@ -15,7 +15,7 @@ This package may not cover all the use cases for btrfs. If something you need
 is missing, please don't hesitate to submit a PR.
 
 Note that due to struct alignment issues, this isn't yet fully native.
-Preferrably, this could be resolved, so contributions in this direction are
+Preferably, this could be resolved, so contributions in this direction are
 greatly appreciated.
 
 ## Applying License Header to New Files

btrfs.go

@@ -14,25 +14,8 @@
    limitations under the License.
 */
 
-/*
-  Copyright The containerd Authors
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
-*/
 package btrfs
 
-import "sort"
-
 /*
 #include <stddef.h>
 #include <btrfs/ioctl.h>
@@ -47,12 +30,17 @@ import "C"
 import (
 	"os"
 	"path/filepath"
+	"sort"
 	"syscall"
 	"unsafe"
 
 	"github.com/pkg/errors"
 )
 
+// maxByteSliceSize is the smallest size that Go supports on various platforms.
+// On mipsle, 1<<31-1 overflows the address space.
+const maxByteSliceSize = 1 << 30
+
 // IsSubvolume returns nil if the path is a valid subvolume. An error is
 // returned if the path does not exist or the path is not a valid subvolume.
 func IsSubvolume(path string) error {
@@ -146,7 +134,7 @@ func subvolMap(path string) (map[uint64]*Info, error) {
 		var (
 			sh     C.struct_btrfs_ioctl_search_header
 			shSize = unsafe.Sizeof(sh)
-			buf    = (*[1<<31 - 1]byte)(unsafe.Pointer(&args.buf[0]))[:C.BTRFS_SEARCH_ARGS_BUFSIZE]
+			buf    = (*[maxByteSliceSize]byte)(unsafe.Pointer(&args.buf[0]))[:C.BTRFS_SEARCH_ARGS_BUFSIZE]
 		)
 
 		for i := 0; i < int(args.key.nr_items); i++ {
@@ -287,7 +275,7 @@ func SubvolCreate(path string) error {
 	if len(name) > C.BTRFS_PATH_NAME_MAX {
 		return errors.Errorf("%q too long for subvolume", name)
 	}
-	nameptr := (*[1<<31 - 1]byte)(unsafe.Pointer(&args.name[0]))
+	nameptr := (*[maxByteSliceSize]byte)(unsafe.Pointer(&args.name[0]))
 	copy(nameptr[:C.BTRFS_PATH_NAME_MAX], []byte(name))
 
 	if err := ioctl(fp.Fd(), C.BTRFS_IOC_SUBVOL_CREATE, uintptr(unsafe.Pointer(&args))); err != nil {
@@ -304,7 +292,7 @@ func SubvolSnapshot(dst, src string, readonly bool) error {
 
 	dstfp, err := openSubvolDir(dstdir)
 	if err != nil {
-		return errors.Wrapf(err, "opening snapshot desination subvolume failed")
+		return errors.Wrapf(err, "opening snapshot destination subvolume failed")
 	}
 	defer dstfp.Close()
 
@@ -323,7 +311,7 @@ func SubvolSnapshot(dst, src string, readonly bool) error {
 		return errors.Errorf("%q too long for subvolume", dstname)
 	}
 
-	nameptr := (*[1<<31 - 1]byte)(unsafe.Pointer(name))
+	nameptr := (*[maxByteSliceSize]byte)(unsafe.Pointer(name))
 	copy(nameptr[:C.BTRFS_SUBVOL_NAME_MAX], []byte(dstname))
 
 	if readonly {
@@ -382,7 +370,7 @@ func SubvolDelete(path string) error {
 		return errors.Errorf("%q too long for subvolume", name)
 	}
 
-	nameptr := (*[1<<31 - 1]byte)(unsafe.Pointer(&args.name[0]))
+	nameptr := (*[maxByteSliceSize]byte)(unsafe.Pointer(&args.name[0]))
 	copy(nameptr[:C.BTRFS_SUBVOL_NAME_MAX], []byte(name))
 
 	if err := ioctl(fp.Fd(), C.BTRFS_IOC_SNAP_DESTROY, uintptr(unsafe.Pointer(&args))); err != nil {

doc.go

@@ -14,20 +14,5 @@
    limitations under the License.
 */
 
-/*
-  Copyright The containerd Authors
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
-*/
 // Package btrfs provides bindings for working with btrfs partitions from Go.
 package btrfs

helpers.go

@@ -14,21 +14,6 @@
    limitations under the License.
 */
 
-/*
-  Copyright The containerd Authors
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
-*/
 package btrfs
 
 /*
@@ -66,7 +51,7 @@ var (
 )
 
 func uuidString(uuid *[C.BTRFS_UUID_SIZE]C.u8) string {
-	b := (*[1<<31 - 1]byte)(unsafe.Pointer(uuid))[:C.BTRFS_UUID_SIZE]
+	b := (*[maxByteSliceSize]byte)(unsafe.Pointer(uuid))[:C.BTRFS_UUID_SIZE]
 
 	if bytes.Equal(b, zeros) {
 		return ""

info.go

@@ -14,21 +14,6 @@
    limitations under the License.
 */
 
-/*
-  Copyright The containerd Authors
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
-*/
 package btrfs
 
 // Info describes metadata about a btrfs subvolume.

ioctl.go

@@ -14,21 +14,6 @@
    limitations under the License.
 */
 
-/*
-  Copyright The containerd Authors
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
-*/
 package btrfs
 
 import "syscall"