58 lines
1.7 KiB
Go
58 lines
1.7 KiB
Go
// Copyright 2019 The gVisor Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package ext
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import (
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"io"
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"gvisor.dev/gvisor/pkg/syserror"
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)
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// symlink represents a symlink inode.
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type symlink struct {
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inode inode
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target string // immutable
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}
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// newSymlink is the symlink constructor. It reads out the symlink target from
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// the inode (however it might have been stored).
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func newSymlink(dev io.ReaderAt, blkSize uint64, inode inode) (*symlink, error) {
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var file *symlink
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var link []byte
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// If the symlink target is lesser than 60 bytes, its stores in inode.Data().
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// Otherwise either extents or block maps will be used to store the link.
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size := inode.diskInode.Size()
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if size < 60 {
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link = inode.diskInode.Data()[:size]
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} else {
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// Create a regular file out of this inode and read out the target.
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regFile, err := newRegularFile(dev, blkSize, inode)
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if err != nil {
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return nil, err
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}
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link = make([]byte, size)
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reader := regFile.impl.getFileReader(dev, blkSize, 0)
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if _, err := io.ReadFull(reader, link); err != nil {
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return nil, syserror.EIO
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}
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}
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file = &symlink{inode: inode, target: string(link)}
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file.inode.impl = file
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return file, nil
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}
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