DAOS-18690 vos: fix engine crash when extend committed DTX table

[Nasf-Fan]

PR#18141 (b36dd7b) introduced some regression:

When the pool is physically full (ENOSPC), extending committed DTX table for punch/update commit may crash the whole engine with SIGABRT. That is because the backend TX logic (such as PMDK) will abort the TX by default if hit failure when allocation. Then subsequent operation (such as tx_add_ptr that is triggered by vos_dtx_extend_cmt_table()) against such aborted backend TX will trigger assertion inside backend TX logic.

The patch replaces umem_zalloc() with umem_alloc_verb() for extending committed DTX table with new UMEM_FLAG_NO_ABORT flag that will notify backend TX logic to return ENOSPC without aborted related TX. Similar enhancement is also added for tx_add_ptr related logic.

New unit tests (UMEM010/BMEM016/BMEM024) for that.

Steps for the author:

• Commit message follows the guidelines.
• Appropriate Features or Test-tag pragmas were used.
• Appropriate Functional Test Stages were run.
• At least two positive code reviews including at least one code owner from each category referenced in the PR.
• Testing is complete. If necessary, forced-landing label added and a reason added in a comment.

After all prior steps are complete:

• Gatekeeper requested (daos-gatekeeper added as a reviewer).

[github-actions]

Ticket title is 'Aurora daos_user: SCM single target ran out of space (min:0 B) and not able to finish GC. '
Status is 'In Progress'
Labels: 'request_for_2.8.1'
https://daosio.atlassian.net/browse/DAOS-18690

[daosbuild3]

Test stage Unit Test completed with status UNSTABLE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net/job/daos-stack/job/daos//view/change-requests/job/PR-18671/2/testReport/

[daosbuild3]

Test stage Unit Test with memcheck completed with status UNSTABLE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net/job/daos-stack/job/daos//view/change-requests/job/PR-18671/2/testReport/

[hgichon]

Thanks @Nasf-Fan — cross-checked against #18612 and everything landed: flag consistency, full failure_behavior unwind (no dangling refs), and the commit path (vos_dtx_commit_internal) is fully NO_ABORT-protected, so the crash can't recur. Nice that UMEM010 now covers the xadd_ptr path too. LGTM.

Two non-blocking checks:

1. vos_dtx_extend_act_table() / vos_dtx_set_flags_one() reverted to plain umem_tx_add_ptr() (abort on failure) — intentional for those non-commit paths?
2. UMEM010 runs under setup_pmem only; the reported crash was on md-on-SSD (DAV). Same coverage as #18612, just flagging in case a bmem variant is wanted.

[Nasf-Fan]

Thanks @Nasf-Fan — cross-checked against #18612 and everything landed: flag consistency, full failure_behavior unwind (no dangling refs), and the commit path (vos_dtx_commit_internal) is fully NO_ABORT-protected, so the crash can't recur. Nice that UMEM010 now covers the xadd_ptr path too. LGTM.

Two non-blocking checks:

1. vos_dtx_extend_act_table() / vos_dtx_set_flags_one() reverted to plain umem_tx_add_ptr() (abort on failure) — intentional for those non-commit paths?

vos_dtx_add_ptr() is used to handle space pressure when we try to release some space (directly or indirectly), such as DTX aggregation or DTX commit. But vos_dtx_extend_act_table() is during update/punch processing that will consume more space, even if we use vos_dtx_add_ptr(), related modification itself will also consume more space and maybe out of space when space pressure. So they are not the candidate users for vos_dtx_add_ptr().

2. UMEM010 runs under setup_pmem only; the reported crash was on md-on-SSD (DAV). Same coverage as DAOS-18690 vos: fix engine abort in DTX commit blob fallback on ENOSPC #18612, just flagging in case a bmem variant is wanted.

I will add new test cases to cover bmem and bmem_v2.

[daosbuild3]

Test stage Unit Test completed with status UNSTABLE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net/job/daos-stack/job/daos//view/change-requests/job/PR-18671/4/testReport/

[daosbuild3]

Test stage Unit Test with memcheck completed with status UNSTABLE. https://jenkins-3.daos.hpc.amslabs.hpecorp.net/job/daos-stack/job/daos//view/change-requests/job/PR-18671/4/testReport/