|SUCCESS| net/tap: close old LSC socket on netns change

[dpdklab at iol.unh.edu]

Test-Label: ai-code-review
Test-Status: SUCCESS
https://dpdk.org/patch/172369

_AI Code Review_

=== Patch Review: series.patch (via Claude) ===
Review date: 2026-11-03

# DPDK Patch Review

## ERRORS

None identified.

## WARNINGS

None identified.

## INFO

**Resource leak fix looks correct**

The patch addresses a file descriptor leak that occurs when a TAP interface is moved to a new namespace. The previous code created a new netlink socket but never closed the old one before updating the interrupt handle FD.

The fix correctly:
1. Creates the new socket first (`tap_nl_init()`)
2. Validates the new socket before proceeding
3. Closes the old socket only after the new one succeeds (`tap_nl_final()`)
4. Updates the interrupt handle with the new FD

This ordering ensures the handle never references a closed FD if socket creation fails, which is good error-path design.

**Code pattern is consistent with existing cleanup**

The use of `tap_nl_final()` matches the cleanup already present in the `else` branch (line not shown in patch context but implied by the existing code structure). The check `>= 0` for a valid FD is appropriate since -1 is used as the error/invalid value throughout DPDK.

Review-Result: CLEAN