Vendor after merging c/image#536

... which adds blob info caching

Signed-off-by: Miloslav Trmač <mitr@redhat.com>

vendor/github.com/containers/storage/drivers/copy/copy.go

@@ -0,0 +1,277 @@
+// +build linux
+
+package copy
+
+/*
+#include <linux/fs.h>
+
+#ifndef FICLONE
+#define FICLONE		_IOW(0x94, 9, int)
+#endif
+*/
+import "C"
+import (
+	"container/list"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"syscall"
+	"time"
+
+	"github.com/containers/storage/pkg/pools"
+	"github.com/containers/storage/pkg/system"
+	rsystem "github.com/opencontainers/runc/libcontainer/system"
+	"golang.org/x/sys/unix"
+)
+
+// Mode indicates whether to use hardlink or copy content
+type Mode int
+
+const (
+	// Content creates a new file, and copies the content of the file
+	Content Mode = iota
+	// Hardlink creates a new hardlink to the existing file
+	Hardlink
+)
+
+func copyRegular(srcPath, dstPath string, fileinfo os.FileInfo, copyWithFileRange, copyWithFileClone *bool) error {
+	srcFile, err := os.Open(srcPath)
+	if err != nil {
+		return err
+	}
+	defer srcFile.Close()
+
+	// If the destination file already exists, we shouldn't blow it away
+	dstFile, err := os.OpenFile(dstPath, os.O_WRONLY|os.O_CREATE|os.O_EXCL, fileinfo.Mode())
+	if err != nil {
+		return err
+	}
+	defer dstFile.Close()
+
+	if *copyWithFileClone {
+		_, _, err = unix.Syscall(unix.SYS_IOCTL, dstFile.Fd(), C.FICLONE, srcFile.Fd())
+		if err == nil {
+			return nil
+		}
+
+		*copyWithFileClone = false
+		if err == unix.EXDEV {
+			*copyWithFileRange = false
+		}
+	}
+	if *copyWithFileRange {
+		err = doCopyWithFileRange(srcFile, dstFile, fileinfo)
+		// Trying the file_clone may not have caught the exdev case
+		// as the ioctl may not have been available (therefore EINVAL)
+		if err == unix.EXDEV || err == unix.ENOSYS {
+			*copyWithFileRange = false
+		} else {
+			return err
+		}
+	}
+	return legacyCopy(srcFile, dstFile)
+}
+
+func doCopyWithFileRange(srcFile, dstFile *os.File, fileinfo os.FileInfo) error {
+	amountLeftToCopy := fileinfo.Size()
+
+	for amountLeftToCopy > 0 {
+		n, err := unix.CopyFileRange(int(srcFile.Fd()), nil, int(dstFile.Fd()), nil, int(amountLeftToCopy), 0)
+		if err != nil {
+			return err
+		}
+
+		amountLeftToCopy = amountLeftToCopy - int64(n)
+	}
+
+	return nil
+}
+
+func legacyCopy(srcFile io.Reader, dstFile io.Writer) error {
+	_, err := pools.Copy(dstFile, srcFile)
+
+	return err
+}
+
+func copyXattr(srcPath, dstPath, attr string) error {
+	data, err := system.Lgetxattr(srcPath, attr)
+	if err != nil {
+		return err
+	}
+	if data != nil {
+		if err := system.Lsetxattr(dstPath, attr, data, 0); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+type fileID struct {
+	dev uint64
+	ino uint64
+}
+
+type dirMtimeInfo struct {
+	dstPath *string
+	stat    *syscall.Stat_t
+}
+
+// DirCopy copies or hardlinks the contents of one directory to another,
+// properly handling xattrs, and soft links
+//
+// Copying xattrs can be opted out of by passing false for copyXattrs.
+func DirCopy(srcDir, dstDir string, copyMode Mode, copyXattrs bool) error {
+	copyWithFileRange := true
+	copyWithFileClone := true
+
+	// This is a map of source file inodes to dst file paths
+	copiedFiles := make(map[fileID]string)
+
+	dirsToSetMtimes := list.New()
+	err := filepath.Walk(srcDir, func(srcPath string, f os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		// Rebase path
+		relPath, err := filepath.Rel(srcDir, srcPath)
+		if err != nil {
+			return err
+		}
+
+		dstPath := filepath.Join(dstDir, relPath)
+		if err != nil {
+			return err
+		}
+
+		stat, ok := f.Sys().(*syscall.Stat_t)
+		if !ok {
+			return fmt.Errorf("Unable to get raw syscall.Stat_t data for %s", srcPath)
+		}
+
+		isHardlink := false
+
+		switch f.Mode() & os.ModeType {
+		case 0: // Regular file
+			id := fileID{dev: stat.Dev, ino: stat.Ino}
+			if copyMode == Hardlink {
+				isHardlink = true
+				if err2 := os.Link(srcPath, dstPath); err2 != nil {
+					return err2
+				}
+			} else if hardLinkDstPath, ok := copiedFiles[id]; ok {
+				if err2 := os.Link(hardLinkDstPath, dstPath); err2 != nil {
+					return err2
+				}
+			} else {
+				if err2 := copyRegular(srcPath, dstPath, f, &copyWithFileRange, &copyWithFileClone); err2 != nil {
+					return err2
+				}
+				copiedFiles[id] = dstPath
+			}
+
+		case os.ModeDir:
+			if err := os.Mkdir(dstPath, f.Mode()); err != nil && !os.IsExist(err) {
+				return err
+			}
+
+		case os.ModeSymlink:
+			link, err := os.Readlink(srcPath)
+			if err != nil {
+				return err
+			}
+
+			if err := os.Symlink(link, dstPath); err != nil {
+				return err
+			}
+
+		case os.ModeNamedPipe:
+			fallthrough
+		case os.ModeSocket:
+			if err := unix.Mkfifo(dstPath, stat.Mode); err != nil {
+				return err
+			}
+
+		case os.ModeDevice:
+			if rsystem.RunningInUserNS() {
+				// cannot create a device if running in user namespace
+				return nil
+			}
+			if err := unix.Mknod(dstPath, stat.Mode, int(stat.Rdev)); err != nil {
+				return err
+			}
+
+		default:
+			return fmt.Errorf("unknown file type for %s", srcPath)
+		}
+
+		// Everything below is copying metadata from src to dst. All this metadata
+		// already shares an inode for hardlinks.
+		if isHardlink {
+			return nil
+		}
+
+		if err := os.Lchown(dstPath, int(stat.Uid), int(stat.Gid)); err != nil {
+			return err
+		}
+
+		if copyXattrs {
+			if err := doCopyXattrs(srcPath, dstPath); err != nil {
+				return err
+			}
+		}
+
+		isSymlink := f.Mode()&os.ModeSymlink != 0
+
+		// There is no LChmod, so ignore mode for symlink. Also, this
+		// must happen after chown, as that can modify the file mode
+		if !isSymlink {
+			if err := os.Chmod(dstPath, f.Mode()); err != nil {
+				return err
+			}
+		}
+
+		// system.Chtimes doesn't support a NOFOLLOW flag atm
+		// nolint: unconvert
+		if f.IsDir() {
+			dirsToSetMtimes.PushFront(&dirMtimeInfo{dstPath: &dstPath, stat: stat})
+		} else if !isSymlink {
+			aTime := time.Unix(int64(stat.Atim.Sec), int64(stat.Atim.Nsec))
+			mTime := time.Unix(int64(stat.Mtim.Sec), int64(stat.Mtim.Nsec))
+			if err := system.Chtimes(dstPath, aTime, mTime); err != nil {
+				return err
+			}
+		} else {
+			ts := []syscall.Timespec{stat.Atim, stat.Mtim}
+			if err := system.LUtimesNano(dstPath, ts); err != nil {
+				return err
+			}
+		}
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+	for e := dirsToSetMtimes.Front(); e != nil; e = e.Next() {
+		mtimeInfo := e.Value.(*dirMtimeInfo)
+		ts := []syscall.Timespec{mtimeInfo.stat.Atim, mtimeInfo.stat.Mtim}
+		if err := system.LUtimesNano(*mtimeInfo.dstPath, ts); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func doCopyXattrs(srcPath, dstPath string) error {
+	if err := copyXattr(srcPath, dstPath, "security.capability"); err != nil {
+		return err
+	}
+
+	// We need to copy this attribute if it appears in an overlay upper layer, as
+	// this function is used to copy those. It is set by overlay if a directory
+	// is removed and then re-created and should not inherit anything from the
+	// same dir in the lower dir.
+	return copyXattr(srcPath, dstPath, "trusted.overlay.opaque")
+}