[Blockstore] Close split local sglist before replying on error

[EvgeniyKozev]

Problem

TCompositeRequest::OnSubResponse() completed the parent promise before closing the parent TGuardedSgList when a local subrequest failed.

NThreading::TPromise::SetValue() invokes subscribed callbacks synchronously. A callback can therefore move the original TWriteBlocksLocalRequest while OnSubResponse() is still on the stack. The following Request->Sglist.Close() then runs on a moved-from TGuardedSgList and aborts on Y_ABORT_UNLESS(GuardedObject).

Fix

Close the parent local sglist before completing the parent promise. This cancels sibling subrequests before any user-visible callback can run or move the original request.

Regression test

Added TSplitRequestServiceReentrantTest::ShouldCloseLocalSglistBeforeCompletingOnSubRequestError.

The test:

• splits a WriteBlocksLocal request into two subrequests;
• completes the first subrequest with an error;
• subscribes a reentrant callback to the parent future;
• verifies the second subrequest sglist is already closed inside that callback;
• moves the original request from the callback, reproducing the old abort condition.

Before the fix, the test aborts in TGuardedSgList::Close(). With the new ordering, it completes with E_REJECTED.

Testing

Not run locally because this environment does not contain an NBS checkout/build toolchain. The focused CI command is:

./ya make -tt cloud/blockstore/libs/service/ut \
    -F TSplitRequestServiceReentrantTest::ShouldCloseLocalSglistBeforeCompletingOnSubRequestError

[github-actions]

Note

This is an automated comment that will be appended during run.

Note

All workloads for linux-x86_64-relwithdebinfo have completed.

Tip

Planned checks for linux-x86_64-relwithdebinfo.

• ✅ blockstore

🟢 linux-x86_64-relwithdebinfo target: cloud/blockstore/ (test time: 1088s): all tests PASSED for commit fcef562.

TESTS	PASSED	ERRORS	FAILED	FAILED BUILD	SKIPPED	MUTED?
6570	6569	0	0	0	1	0