[PATCH v4 6/6] refs: skip hooks when deleting uncovered packed refs
- From
Patrick Steinhardt <ps@pks.im>
- Date
- Jan 17, 2022, 08:12 UTC
- Message-ID
- <d6c7d765aff13df449d61f0f6efbeb66fe86006d.1642406989.git.ps@pks.im>
- In-Reply-To
- <cover.1642406989.git.ps@pks.im>
When deleting refs from the loose-files refs backend, then we need to be careful to also delete the same ref from the packed refs backend, if it exists. If we don't, then deleting the loose ref would "uncover" the packed ref. We thus always have to queue up deletions of refs for both the loose and the packed refs backend. This is done in two separate transactions, where the end result is that the reference-transaction hook is executed twice for the deleted refs.
This behaviour is quite misleading: it's exposing implementation details of how the files backend works to the user, in contrast to the logical updates that we'd really want to expose via the hook. Worse yet, whether the hook gets executed once or twice depends on how well-packed the repository is: if the ref only exists as a loose ref, then we execute it once, otherwise if it is also packed then we execute it twice.
Fix this behaviour and don't execute the reference-transaction hook at all when refs in the packed-refs backend if it's driven by the files backend. This works as expected even in case the refs to be deleted only exist in the packed-refs backend because the loose-backend always queues refs in its own transaction even if they don't exist such that they can be locked for concurrent creation. And it also does the right thing in case neither of the backends has the ref because that would cause the transaction to fail completely.
Signed-off-by: Patrick Steinhardt <ps@pks.im> --- refs/files-backend.c | 9 ++++++--- t/t1416-ref-transaction-hooks.sh | 7 +------ 2 files changed, 7 insertions(+), 9 deletions(-)
diff --git a/refs/files-backend.c b/refs/files-backend.c index 565929210a..844918cbd8 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -1261,7 +1261,8 @@ static int files_delete_refs(struct ref_store *ref_store, const char *msg, if (packed_refs_lock(refs->packed_ref_store, 0, &err)) goto error; - transaction = ref_store_transaction_begin(refs->packed_ref_store, 0, &err); + transaction = ref_store_transaction_begin(refs->packed_ref_store, + REF_TRANSACTION_SKIP_HOOK, &err); if (!transaction) goto error; @@ -2776,7 +2777,8 @@ static int files_transaction_prepare(struct ref_store *ref_store, */ if (!packed_transaction) { packed_transaction = ref_store_transaction_begin( - refs->packed_ref_store, 0, err); + refs->packed_ref_store, + REF_TRANSACTION_SKIP_HOOK, err); if (!packed_transaction) { ret = TRANSACTION_GENERIC_ERROR; goto cleanup; @@ -3047,7 +3049,8 @@ static int files_initial_transaction_commit(struct ref_store *ref_store, &affected_refnames)) BUG("initial ref transaction called with existing refs"); - packed_transaction = ref_store_transaction_begin(refs->packed_ref_store, 0, err); + packed_transaction = ref_store_transaction_begin(refs->packed_ref_store, + REF_TRANSACTION_SKIP_HOOK, err); if (!packed_transaction) { ret = TRANSACTION_GENERIC_ERROR; goto cleanup; diff --git a/t/t1416-ref-transaction-hooks.sh b/t/t1416-ref-transaction-hooks.sh index f9d3d5213f..4e1e84a91f 100755 --- a/t/t1416-ref-transaction-hooks.sh +++ b/t/t1416-ref-transaction-hooks.sh @@ -175,16 +175,11 @@ test_expect_success 'deleting packed ref calls hook once' ' git update-ref -d refs/heads/to-be-deleted $POST_OID && # We only expect a single hook invocation, which is the logical - # deletion. But currently, we see two interleaving transactions, once - # for deleting the loose refs and once for deleting the packed ref. + # deletion. cat >expect <<-EOF && - prepared - $ZERO_OID $ZERO_OID refs/heads/to-be-deleted prepared $POST_OID $ZERO_OID refs/heads/to-be-deleted committed - $ZERO_OID $ZERO_OID refs/heads/to-be-deleted - committed $POST_OID $ZERO_OID refs/heads/to-be-deleted EOF
-- 2.34.1