Merge branch 'master' into pr_lazy_fpsimd_2

1 files changed, 47 insertions, 0 deletions

diff --git a/pkg/sentry/fsimpl/gofer/symlink.go b/pkg/sentry/fsimpl/gofer/symlink.go
new file mode 100644
index 000000000..adf43be60
--- /dev/null
+++ b/pkg/sentry/fsimpl/gofer/symlink.go
@@ -0,0 +1,47 @@
+// Copyright 2019 The gVisor 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 gofer
+
+import (
+	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/context"
+	"gvisor.dev/gvisor/pkg/sentry/vfs"
+)
+
+func (d *dentry) isSymlink() bool {
+	return d.fileType() == linux.S_IFLNK
+}
+
+// Precondition: d.isSymlink().
+func (d *dentry) readlink(ctx context.Context, mnt *vfs.Mount) (string, error) {
+	if d.fs.opts.interop != InteropModeShared {
+		d.touchAtime(ctx, mnt)
+		d.dataMu.Lock()
+		if d.haveTarget {
+			target := d.target
+			d.dataMu.Unlock()
+			return target, nil
+		}
+	}
+	target, err := d.file.readlink(ctx)
+	if d.fs.opts.interop != InteropModeShared {
+		if err == nil {
+			d.haveTarget = true
+			d.target = target
+		}
+		d.dataMu.Unlock()
+	}
+	return target, err
+}