Multiple data race issues

[wongak]

Describe the bug
tusd.Config{} Logger is set. When performing an upload a data race is reported:

==================
WARNING: DATA RACE
Write at 0x00c0006ae3b0 by goroutine 349:
  github.com/tus/tusd/v2/pkg/handler.(*UnroutedHandler).PostFile()
      .../vendor/github.com/tus/tusd/v2/pkg/handler/unrouted_handler.go:398 +0xb60
...
Previous read at 0x00c0006ae3b0 by goroutine 398:
  github.com/tus/tusd/v2/pkg/handler.(*httpContext).Value()
      <autogenerated>:1 +0x44

To Reproduce
Steps to reproduce the behavior:

1. Configure a logger
2. Run with -race

Currently still investigating which other circumstances lead to this.

But

	c.log = c.log.With("id", id)

writing to a context without creating a copy is probably not correct.

Expected behavior
No data race should happen

Setup details
Please provide following details, if applicable to your situation:

• Operating System: macOS
• Used tusd version: github.com/tus/tusd/v2 v2.4.0
• Used tusd data storage: S3 with local minio

[wongak]

Unfortunately this uncovers quite a few more data race issues, which go beyond the scope of this issue:

==================
WARNING: DATA RACE
Write at 0x00c0000c40a0 by goroutine 205:
  github.com/tus/tusd/v2/pkg/handler.(*bodyReader).closeWithError()
      .../tusd/pkg/handler/body_reader.go:123 +0x3c
  github.com/tus/tusd/v2/pkg/handler.UnroutedHandler.newContext.func1()
      .../tusd/pkg/handler/context.go:66 +0x13c

Previous read at 0x00c0000c40a0 by goroutine 202:
  github.com/tus/tusd/v2/pkg/handler.(*bodyReader).Read()
      .../tusd/pkg/handler/body_reader.go:44 +0x40
  io.ReadAll()
      .../go/1.23.1/libexec/src/io/io.go:712 +0x84

and

==================
WARNING: DATA RACE
Write at 0x00c0002180e0 by goroutine 130:
  github.com/tus/tusd/v2/pkg/s3store.(*s3Upload).uploadParts.func2()
      .../tusd/pkg/s3store/s3store.go:515 +0x4dc
  github.com/tus/tusd/v2/pkg/s3store.(*s3Upload).uploadParts.gowrap2()
      .../tusd/pkg/s3store/s3store.go:522 +0x6c

Previous write at 0x00c0002180e0 by goroutine 131:
  github.com/tus/tusd/v2/pkg/s3store.(*s3Upload).uploadParts.func2()
      .../tusd/pkg/s3store/s3store.go:515 +0x4dc
  github.com/tus/tusd/v2/pkg/s3store.(*s3Upload).uploadParts.gowrap2()
      .../tusd/pkg/s3store/s3store.go:522 +0x6c

[wongak]

Updated the issue. This requires a rework of the context implementation.

[Acconut]

Thank you for bringing this up! I haven't used the data race detector before, so tusd hasn't been vetted by it so far, but we should change this.

Running the race detector during tests also shows a few issues (go test -race ./pkg/handler/). Most of these should likely be easy to address through the use of sync/atomic. For the logger, we can move the call to .With("id", id) when constructing the context in the first place.

I'll have a look at them soon.

[Acconut]

Opened #1199.

[Acconut]

I addressed the data races in handler and s3store in #1199, but not the logger-related one yet.

[Acconut]

We don't seem to be able to reproduce this specific data race anymore (see #1193 (comment)). Since the other races have been fixed, I will close this issue for now. Feel free to reopen it if the problem appears again.