Backport erofs snapshotter into containerd2

[aadhar-agarwal]

Merge Checklist

All boxes should be checked before merging the PR (just tick any boxes which don't apply to this PR)

• The toolchain has been rebuilt successfully (or no changes were made to it)
• The toolchain/worker package manifests are up-to-date
• Any updated packages successfully build (or no packages were changed)
• Packages depending on static components modified in this PR (Golang, *-static subpackages, etc.) have had their Release tag incremented.
• Package tests (%check section) have been verified with RUN_CHECK=y for existing SPEC files, or added to new SPEC files
• All package sources are available
• cgmanifest files are up-to-date and sorted (./cgmanifest.json, ./toolkit/scripts/toolchain/cgmanifest.json, .github/workflows/cgmanifest.json)
• LICENSE-MAP files are up-to-date (./LICENSES-AND-NOTICES/SPECS/data/licenses.json, ./LICENSES-AND-NOTICES/SPECS/LICENSES-MAP.md, ./LICENSES-AND-NOTICES/SPECS/LICENSE-EXCEPTIONS.PHOTON)
• All source files have up-to-date hashes in the *.signatures.json files
• sudo make go-tidy-all and sudo make go-test-coverage pass
• Documentation has been updated to match any changes to the build system
• Ready to merge

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Summary

What does the PR accomplish, why was it needed?

• This PR backports the erofs snapshotter from containerd 2.1.2 into containerd 2.0.0
• It adds 2 patches:
  • One to add the existing erofs snapshotter implementation that exists in 2.1.2
  • One to add additional changes that adds the tar index mode, dmverity and local signature support

Change Log

• containerd2

Does this affect the toolchain?

NO

Test Methodology

• Buddy build - pass

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• [AMD64-3-OneBranch]-Dev-BuildImages - pass
• [ARM64-3-OneBranch]-Dev-BuildImages - pass
• Testing on a normal AKS image:
  • aks-image-build - pass
  • aks-pre-release-tests - running
  • aks-e2e-tests - running
  • aks-core-conformance-tests - running
  • aks-kata-conformance-tests - running

[CBL-Mariner-Bot]

✅ PR Check Passed

No critical issues detected in spec file changes.

🤖 AI Analysis Summary:

Brief Analysis: The changes in containerd2.spec and the accompanying patch files integrate new erofs snapshotter functionality and several CVE fixes properly. All patch references used in the spec match with the files present in the package.

Critical Issues Found: No ERROR/CRITICAL security issues detected.

Recommended Actions:
• Verify that %autosetup (or %patch directives) correctly applies all patches during build.
• Double‐check patch file names and numbering to ensure they adhere strictly to the “CVE-YYYY-XXXXX.patch” format.
• Review the README/changelog entries to confirm all CVE fixes are fully documented with proper attribution.

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📋 For detailed analysis and recommendations, check the Azure DevOps pipeline logs.