diff options
Diffstat (limited to 'vendor/github.com/containerd/continuity/fs/copy_linux.go')
-rw-r--r-- | vendor/github.com/containerd/continuity/fs/copy_linux.go | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/vendor/github.com/containerd/continuity/fs/copy_linux.go b/vendor/github.com/containerd/continuity/fs/copy_linux.go new file mode 100644 index 000000000..81c71522a --- /dev/null +++ b/vendor/github.com/containerd/continuity/fs/copy_linux.go @@ -0,0 +1,144 @@ +/* + 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 fs + +import ( + "io" + "os" + "syscall" + + "github.com/containerd/continuity/sysx" + "github.com/pkg/errors" + "golang.org/x/sys/unix" +) + +func copyFileInfo(fi os.FileInfo, name string) error { + st := fi.Sys().(*syscall.Stat_t) + if err := os.Lchown(name, int(st.Uid), int(st.Gid)); err != nil { + if os.IsPermission(err) { + // Normally if uid/gid are the same this would be a no-op, but some + // filesystems may still return EPERM... for instance NFS does this. + // In such a case, this is not an error. + if dstStat, err2 := os.Lstat(name); err2 == nil { + st2 := dstStat.Sys().(*syscall.Stat_t) + if st.Uid == st2.Uid && st.Gid == st2.Gid { + err = nil + } + } + } + if err != nil { + return errors.Wrapf(err, "failed to chown %s", name) + } + } + + if (fi.Mode() & os.ModeSymlink) != os.ModeSymlink { + if err := os.Chmod(name, fi.Mode()); err != nil { + return errors.Wrapf(err, "failed to chmod %s", name) + } + } + + timespec := []unix.Timespec{unix.Timespec(StatAtime(st)), unix.Timespec(StatMtime(st))} + if err := unix.UtimesNanoAt(unix.AT_FDCWD, name, timespec, unix.AT_SYMLINK_NOFOLLOW); err != nil { + return errors.Wrapf(err, "failed to utime %s", name) + } + + return nil +} + +const maxSSizeT = int64(^uint(0) >> 1) + +func copyFileContent(dst, src *os.File) error { + st, err := src.Stat() + if err != nil { + return errors.Wrap(err, "unable to stat source") + } + + size := st.Size() + first := true + srcFd := int(src.Fd()) + dstFd := int(dst.Fd()) + + for size > 0 { + // Ensure that we are never trying to copy more than SSIZE_MAX at a + // time and at the same time avoids overflows when the file is larger + // than 4GB on 32-bit systems. + var copySize int + if size > maxSSizeT { + copySize = int(maxSSizeT) + } else { + copySize = int(size) + } + n, err := unix.CopyFileRange(srcFd, nil, dstFd, nil, copySize, 0) + if err != nil { + if (err != unix.ENOSYS && err != unix.EXDEV) || !first { + return errors.Wrap(err, "copy file range failed") + } + + buf := bufferPool.Get().(*[]byte) + _, err = io.CopyBuffer(dst, src, *buf) + bufferPool.Put(buf) + return errors.Wrap(err, "userspace copy failed") + } + + first = false + size -= int64(n) + } + + return nil +} + +func copyXAttrs(dst, src string, xeh XAttrErrorHandler) error { + xattrKeys, err := sysx.LListxattr(src) + if err != nil { + e := errors.Wrapf(err, "failed to list xattrs on %s", src) + if xeh != nil { + e = xeh(dst, src, "", e) + } + return e + } + for _, xattr := range xattrKeys { + data, err := sysx.LGetxattr(src, xattr) + if err != nil { + e := errors.Wrapf(err, "failed to get xattr %q on %s", xattr, src) + if xeh != nil { + if e = xeh(dst, src, xattr, e); e == nil { + continue + } + } + return e + } + if err := sysx.LSetxattr(dst, xattr, data, 0); err != nil { + e := errors.Wrapf(err, "failed to set xattr %q on %s", xattr, dst) + if xeh != nil { + if e = xeh(dst, src, xattr, e); e == nil { + continue + } + } + return e + } + } + + return nil +} + +func copyDevice(dst string, fi os.FileInfo) error { + st, ok := fi.Sys().(*syscall.Stat_t) + if !ok { + return errors.New("unsupported stat type") + } + return unix.Mknod(dst, uint32(fi.Mode()), int(st.Rdev)) +} |