[PATCH v12 2/8] refs: atomically record overwritten ref in update_symref
From: Bence Ferdinandy <hidden>
Date: 2024-10-23 15:38:59
Subsystem:
the rest · Maintainer:
Linus Torvalds
Possibly related (same subject, not in this thread)
- 2024-11-18 · Re: [PATCH v12 2/8] refs: atomically record overwritten ref in update_symref · Bence Ferdinandy <hidden>
- 2024-11-18 · Re: [PATCH v12 2/8] refs: atomically record overwritten ref in update_symref · Patrick Steinhardt <hidden>
- 2024-11-18 · Re: [PATCH v12 2/8] refs: atomically record overwritten ref in update_symref · Bence Ferdinandy <hidden>
- 2024-11-18 · Re: [PATCH v12 2/8] refs: atomically record overwritten ref in update_symref · Patrick Steinhardt <hidden>
- 2024-11-18 · Re: [PATCH v12 2/8] refs: atomically record overwritten ref in update_symref · Junio C Hamano <hidden>
When updating a symref with update_symref it's currently not possible to
know for sure what was the previous value that was overwritten. Extend
refs_update_symref under a new function name, to record the value after
the ref has been locked if the caller of refs_update_symref_extended
requests it via a new variable in the function call. Keep the original
refs_update_symref function with the same signature, but now as
a wrapper around refs_update_symref_extended.
Signed-off-by: Bence Ferdinandy <redacted>
---
Notes:
v4: new patch
v5: - added before_target to reftables backend
- added an extra safety check for transaction's existence in refs.c
v6: - no change
v7: - remove the whole before_target concept from the backends and
handle checking it in refs.c instead (thanks Karthik)
- rename the before_target to referent which is how the same concept
is called in the backends
- change commit prefix to be more in line with project standards
v8: no change
v9: - instead of adding parameters to refs_update_symref, rename what
was in v8 as refs_update_symref_extended and make refs_update_symref
a wrapper for that. This significantly reduces the number of files
that need to be touched, and avoids adding a lot of dummy NULL-s
in unrelated places.
v10: no change
v11: no change
v12: no change
refs.c | 19 ++++++++++++++++---
refs.h | 4 ++++
2 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/refs.c b/refs.c
index 5f729ed412..24a4172cd2 100644
--- a/refs.c
+++ b/refs.c@@ -2115,6 +2115,13 @@ int peel_iterated_oid(struct repository *r, const struct object_id *base, struct int refs_update_symref(struct ref_store *refs, const char *ref, const char *target, const char *logmsg) +{ + return refs_update_symref_extended(refs, ref, target, logmsg, NULL); +} + +int refs_update_symref_extended(struct ref_store *refs, const char *ref, + const char *target, const char *logmsg, + struct strbuf *referent) { struct ref_transaction *transaction; struct strbuf err = STRBUF_INIT;
@@ -2122,13 +2129,20 @@ int refs_update_symref(struct ref_store *refs, const char *ref, transaction = ref_store_transaction_begin(refs, &err); if (!transaction || - ref_transaction_update(transaction, ref, NULL, NULL, + ref_transaction_update(transaction, ref, NULL, NULL, target, NULL, REF_NO_DEREF, logmsg, &err) || - ref_transaction_commit(transaction, &err)) { + ref_transaction_prepare(transaction, &err)) { ret = error("%s", err.buf); + goto cleanup; } + if (referent) + refs_read_symbolic_ref(refs, ref, referent); + if (ref_transaction_commit(transaction, &err)) + ret = error("%s", err.buf); + +cleanup: strbuf_release(&err); if (transaction) ref_transaction_free(transaction);
@@ -2948,4 +2962,3 @@ int ref_update_expects_existing_old_ref(struct ref_update *update) return (update->flags & REF_HAVE_OLD) && (!is_null_oid(&update->old_oid) || update->old_target); } -
diff --git a/refs.h b/refs.h
index 108dfc93b3..259191a485 100644
--- a/refs.h
+++ b/refs.h@@ -573,6 +573,10 @@ int refs_copy_existing_ref(struct ref_store *refs, const char *oldref, int refs_update_symref(struct ref_store *refs, const char *refname, const char *target, const char *logmsg); +int refs_update_symref_extended(struct ref_store *refs, const char *refname, + const char *target, const char *logmsg, + struct strbuf *referent); + enum action_on_err { UPDATE_REFS_MSG_ON_ERR, UPDATE_REFS_DIE_ON_ERR,
--
2.47.0.94.g1247fb88fd.dirty