vendor: update buildkit to master@9624ab4

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

vendor/github.com/containerd/continuity/fs/copy_linux.go

@@ -0,0 +1,145 @@
+/*
+   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 (
+	"fmt"
+	"io"
+	"os"
+	"syscall"
+
+	"github.com/containerd/continuity/sysx"
+	"golang.org/x/sys/unix"
+)
+
+func copyFileInfo(fi os.FileInfo, src, 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 fmt.Errorf("failed to chown %s: %w", name, err)
+		}
+	}
+
+	if (fi.Mode() & os.ModeSymlink) != os.ModeSymlink {
+		if err := os.Chmod(name, fi.Mode()); err != nil {
+			return fmt.Errorf("failed to chmod %s: %w", name, err)
+		}
+	}
+
+	timespec := []unix.Timespec{
+		unix.NsecToTimespec(syscall.TimespecToNsec(StatAtime(st))),
+		unix.NsecToTimespec(syscall.TimespecToNsec(StatMtime(st))),
+	}
+	if err := unix.UtimesNanoAt(unix.AT_FDCWD, name, timespec, unix.AT_SYMLINK_NOFOLLOW); err != nil {
+		return fmt.Errorf("failed to utime %s: %w", name, err)
+	}
+
+	return nil
+}
+
+const maxSSizeT = int64(^uint(0) >> 1)
+
+func copyFileContent(dst, src *os.File) error {
+	st, err := src.Stat()
+	if err != nil {
+		return fmt.Errorf("unable to stat source: %w", err)
+	}
+
+	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 fmt.Errorf("copy file range failed: %w", err)
+			}
+
+			buf := bufferPool.Get().(*[]byte)
+			_, err = io.CopyBuffer(dst, src, *buf)
+			bufferPool.Put(buf)
+			if err != nil {
+				return fmt.Errorf("userspace copy failed: %w", err)
+			}
+			return nil
+		}
+
+		first = false
+		size -= int64(n)
+	}
+
+	return nil
+}
+
+func copyXAttrs(dst, src string, excludes map[string]struct{}, errorHandler XAttrErrorHandler) error {
+	xattrKeys, err := sysx.LListxattr(src)
+	if err != nil {
+		e := fmt.Errorf("failed to list xattrs on %s: %w", src, err)
+		if errorHandler != nil {
+			e = errorHandler(dst, src, "", e)
+		}
+		return e
+	}
+	for _, xattr := range xattrKeys {
+		if _, exclude := excludes[xattr]; exclude {
+			continue
+		}
+		data, err := sysx.LGetxattr(src, xattr)
+		if err != nil {
+			e := fmt.Errorf("failed to get xattr %q on %s: %w", xattr, src, err)
+			if errorHandler != nil {
+				if e = errorHandler(dst, src, xattr, e); e == nil {
+					continue
+				}
+			}
+			return e
+		}
+		if err := sysx.LSetxattr(dst, xattr, data, 0); err != nil {
+			e := fmt.Errorf("failed to set xattr %q on %s: %w", xattr, dst, err)
+			if errorHandler != nil {
+				if e = errorHandler(dst, src, xattr, e); e == nil {
+					continue
+				}
+			}
+			return e
+		}
+	}
+
+	return nil
+}