[kke]

Adds remotefs.WithContext(ctx, fsys), which returns a copy of a rig filesystem whose commands run under ctx — option 1 from the issue. It also covers the fs.FS-shaped methods and helpers like Upload. Additive: no exported interface changes.

Fixes #474

🤖 Generated with Claude Code

[github-actions]

Exported API changed by this pull request

Compared against aa1a3e7.

This only adds exported API.

Compared for linux, windows, darwin. Entries read ./package.Symbol; the module root package is unprefixed.

Compatible changes (1):

- ./remotefs.WithContext: added

[Copilot]

🟡 Changes recommended

Context binding can discard third-party wrapper behavior and lose cancellation causes during Windows sessions, while key tests fail before exercising the intended bound-context paths.

4 open issues

• Preserve context cancellation errors through session shutdown · New
• Restrict context binding to exact filesystem types · New
• Fix tests to exercise context-bound operations · New
• Scope cancellation guarantees to context-aware commands · New

What changed in this PR

Adds remotefs.WithContext(ctx, fsys) to let callers bound remote filesystem operations, including standard fs.FS methods and helpers such as Upload, without changing exported interfaces.

Changes:

• Introduces context-bound copies of POSIX and Windows filesystems.
• Propagates the bound context to Windows file sessions, directory listings, and URL downloads.
• Adjusts cached POSIX timestamp handling and adds context-binding tests.

File	Description
remotefs/​withcontext.go	Adds filesystem copying and context-bound runner methods.
remotefs/​withcontext_test.go	Tests binding, cancellation, rebinding, and original filesystem isolation.
remotefs/​winfile.go	Uses the bound context for rigrcp sessions.
remotefs/​windir.go	Uses the bound context for directory listing commands.
remotefs/​posixfs.go	Makes cached timestamp handlers operate on the bound copy.
remotefs/​download.go	Passes the filesystem context into URL downloads.

_{Review effort: Balanced}

[Copilot]

🟡 Changes recommended

Unresolved Windows cancellation bugs allow shell startup to exceed filesystem deadlines, shutdown to report success after cancellation, and failed opens to retain child contexts.

1 open issue

• Avoid claiming expired Windows files can still be seeked · New

3 previously missed issues

In code that hasn't changed since last review

Cancel child context when file daemon startup fails

remotefs/​winfile.go:513

If the initial Stat succeeds but starting the file daemon fails, OpenFile returns no handle and never calls this cancel function. With the new cancellable parent, that leaves the child context registered until the parent's cancellation; repeated failed opens under a long-lived context accumulate retained children. Call cancel() on the Start error path.

Preserve cancellation errors during Windows file shutdown

remotefs/​winfile.go:563

Cancellation during Windows file shutdown can still be reported as success: Close ignores the recorded abort cause after its final wait, and closeWithSession discards context errors returned while closing. Consequently, ReadFile and WriteFile can return nil even when cancellation interrupts shutdown. Check the abort cause after Close's final wait and preserve cancellation/deadline errors in closeWithSession (remotefs/winfs.go:116–120), with regression coverage for both paths.

Honor operation deadlines during WinRM shell startup

remotefs/​withcontext.go:15

A short filesystem deadline still cannot bound WinRM shell startup: StartProcess synchronously calls client.CreateShell() without the operation context (protocol/winrm/connection.go:449). If the host stops answering there, even the initial Stat can block until the connection's HTTP timeout rather than the filesystem deadline. Make shell creation honor the operation context and test cancellation during startup before promising an end-to-end bound.

4 resolved since last review

• Fix tests to exercise context-bound operations
• Restrict context binding to exact filesystem types
• Preserve context cancellation errors through session shutdown
• Scope cancellation guarantees to context-aware commands

_{Review effort: Balanced}

[Copilot]

🔵 Needs a closer look

Cancellation errors are lost during POSIX stat initialization and Windows session cleanup, preventing callers from recognizing cancellation and allowing Windows reads or writes to report success after cancellation.

No open issues 🎉

2 previously missed issues

In code that hasn't changed since last review

Propagate cancellation when closing an ended Windows session

remotefs/​winfile.go:747

If cancellation ends the Windows session before deferred Close starts, command("c") returns fs.ErrClosed before this context-error check is reached. closeWithSession ignores that error, so ReadFile and WriteFile can report success despite the canceled session. Return f.abortCause(fs.ErrClosed) from command's closed-file guard, and add a regression test where the session ends before Close starts.

Preserve context errors during POSIX stat initialization

remotefs/​withcontext.go:45

On a fresh POSIX filesystem, cancellation before or during the first Stat makes initStat discard the probe errors and report an unsupported stat implementation. Callers then cannot recognize cancellation or deadline expiry with errors.Is, including through OpenFile and uploads. Preserve context errors in PosixFS.initStat before falling back or returning errStatInitFailed, and test cancellation before stat initialization.

1 resolved since last review

• Avoid claiming expired Windows files can still be seeked

_{Review effort: Balanced}

[Copilot]

🔵 Needs a closer look

Human assessment is needed to evaluate cancellation-induced timestamp precision loss and gaps in Windows in-flight transfer cancellation coverage.

No open issues 🎉

_{Review effort: Balanced}

[Copilot]

🟡 Changes recommended

The cancellation test retries on the original filesystem instead of the context-bound copy, so it can pass even when cancellation incorrectly caches the seconds-only fallback.

1 open issue

• Retry test uses original filesystem and misses cancelled-copy cache regression · New

_{Review effort: Balanced}

[Copilot]

🔵 Needs a closer look

Human assessment is needed because cancellation can stall Windows file operations until the watchdog fires and cause POSIX probes to cache reduced timestamp precision or misreport cancellation.

No open issues 🎉

1 resolved since last review

• Retry test uses original filesystem and misses cancelled-copy cache regression

_{Review effort: Balanced}