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https://github.com/versity/versitygw.git
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Keith KennedyandClaude Opus 5.5
3979267636
The posix backend publishes an object by linking or renaming a temp file into place, but never flushes it. An acknowledged PUT can therefore be lost, or come back empty, after a crash or power loss, depending on the filesystem's writeback interval. With --fsync (VGW_FSYNC), the backend fsyncs the temp file, which covers its data and xattr metadata, before publishing it. After publishing, it fsyncs the object's directory and each parent up to the bucket, so that the new entry and any directories created for it are durable. A failed flush fails the request. The option is off by default, so existing deployments are unaffected. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
73 lines
1.9 KiB
Go
73 lines
1.9 KiB
Go
// Copyright 2026 Versity Software
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// This file is licensed under the Apache License, Version 2.0
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// (the "License"); you may not use this file except in compliance
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// with the License. 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,
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// software distributed under the License is distributed on an
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// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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// KIND, either express or implied. See the License for the
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// specific language governing permissions and limitations
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// under the License.
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package posix
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import (
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"fmt"
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"os"
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"path/filepath"
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"runtime"
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)
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// syncFile and syncDir are variables so tests can observe the calls.
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var (
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syncFile = func(f *os.File) error { return f.Sync() }
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syncDir = func(dir string) error {
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// Windows cannot fsync a directory handle.
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if runtime.GOOS == "windows" {
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return nil
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}
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d, err := os.Open(dir)
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if err != nil {
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return err
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}
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defer d.Close()
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return d.Sync()
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}
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)
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// syncData flushes an object's data and its inode, which includes the
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// xattr metadata, before the object is published.
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func (tmp *tmpfile) syncData() error {
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if !tmp.fsync {
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return nil
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}
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if err := syncFile(tmp.f); err != nil {
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return fmt.Errorf("fsync object data: %w", err)
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}
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return nil
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}
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// syncNamespace flushes the directory entry that publishes the object, and
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// those of any parent directories created for it, by syncing the object's
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// directory and each parent up to and including the bucket directory.
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func (tmp *tmpfile) syncNamespace() error {
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if !tmp.fsync {
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return nil
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}
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stop := filepath.Clean(tmp.bucket)
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dir := filepath.Dir(filepath.Join(tmp.bucket, tmp.objname))
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for {
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if err := syncDir(dir); err != nil {
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return fmt.Errorf("fsync directory %q: %w", dir, err)
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}
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parent := filepath.Dir(dir)
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if dir == stop || parent == dir {
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return nil
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}
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dir = parent
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}
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}
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