Merge pull request #239 from yylt/magic

support filesystem magic for linux

fs/magic_linux.go

@@ -0,0 +1,123 @@
+/*
+ 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.
+*/
+
+/*
+Copyright 2013-2018 Docker, Inc.
+
+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
+
+ https://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.
+*/
+
+// Original source: https://github.com/moby/moby/blob/v26.0.0/daemon/graphdriver/driver_linux.go
+
+package fs
+
+import (
+ "path/filepath"
+ "syscall"
+)
+
+// Magic unsigned id of the filesystem in use.
+type Magic uint32
+
+const (
+ // MagicUnsupported is a predefined constant value other than a valid filesystem id.
+ MagicUnsupported = Magic(0x00000000)
+)
+
+const (
+ // MagicAufs filesystem id for Aufs
+ MagicAufs = Magic(0x61756673)
+ // MagicBtrfs filesystem id for Btrfs
+ MagicBtrfs = Magic(0x9123683E)
+ // MagicCramfs filesystem id for Cramfs
+ MagicCramfs = Magic(0x28cd3d45)
+ // MagicEcryptfs filesystem id for eCryptfs
+ MagicEcryptfs = Magic(0xf15f)
+ // MagicExtfs filesystem id for Extfs
+ MagicExtfs = Magic(0x0000EF53)
+ // MagicF2fs filesystem id for F2fs
+ MagicF2fs = Magic(0xF2F52010)
+ // MagicGPFS filesystem id for GPFS
+ MagicGPFS = Magic(0x47504653)
+ // MagicJffs2Fs filesystem if for Jffs2Fs
+ MagicJffs2Fs = Magic(0x000072b6)
+ // MagicJfs filesystem id for Jfs
+ MagicJfs = Magic(0x3153464a)
+ // MagicNfsFs filesystem id for NfsFs
+ MagicNfsFs = Magic(0x00006969)
+ // MagicRAMFs filesystem id for RamFs
+ MagicRAMFs = Magic(0x858458f6)
+ // MagicReiserFs filesystem id for ReiserFs
+ MagicReiserFs = Magic(0x52654973)
+ // MagicSmbFs filesystem id for SmbFs
+ MagicSmbFs = Magic(0x0000517B)
+ // MagicSquashFs filesystem id for SquashFs
+ MagicSquashFs = Magic(0x73717368)
+ // MagicTmpFs filesystem id for TmpFs
+ MagicTmpFs = Magic(0x01021994)
+ // MagicVxFS filesystem id for VxFs
+ MagicVxFS = Magic(0xa501fcf5)
+ // MagicXfs filesystem id for Xfs
+ MagicXfs = Magic(0x58465342)
+ // MagicZfs filesystem id for Zfs
+ MagicZfs = Magic(0x2fc12fc1)
+ // MagicOverlay filesystem id for overlay
+ MagicOverlay = Magic(0x794C7630)
+)
+
+var (
+ // FsNames maps filesystem id to name of the filesystem.
+ FsNames = map[Magic]string{
+ MagicAufs: "aufs",
+ MagicBtrfs: "btrfs",
+ MagicCramfs: "cramfs",
+ MagicExtfs: "extfs",
+ MagicF2fs: "f2fs",
+ MagicGPFS: "gpfs",
+ MagicJffs2Fs: "jffs2",
+ MagicJfs: "jfs",
+ MagicNfsFs: "nfs",
+ MagicOverlay: "overlayfs",
+ MagicRAMFs: "ramfs",
+ MagicReiserFs: "reiserfs",
+ MagicSmbFs: "smb",
+ MagicSquashFs: "squashfs",
+ MagicTmpFs: "tmpfs",
+ MagicUnsupported: "unsupported",
+ MagicVxFS: "vxfs",
+ MagicXfs: "xfs",
+ MagicZfs: "zfs",
+ }
+)
+
+// GetMagic returns the filesystem id given the path.
+func GetMagic(rootpath string) (Magic, error) {
+ var buf syscall.Statfs_t
+ if err := syscall.Statfs(filepath.Dir(rootpath), &buf); err != nil {
+ return 0, err
+ }
+ return Magic(buf.Type), nil
+}