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authorJunio C Hamano <gitster@pobox.com>2025-08-21 13:46:57 -0700
committerJunio C Hamano <gitster@pobox.com>2025-08-21 13:46:57 -0700
commitc3c8b6910a7cd3d5a25522d3fd6925083048be24 (patch)
treefe10d063c6c9f4d8d17e3eb10e35f16b5fed0173 /refs
parent1fe6955fd4e0de21a5581376589c8df56fae6adf (diff)
parent465eff81de44763832e96fbe609ec269f1c23ade (diff)
downloadgit-c3c8b6910a7cd3d5a25522d3fd6925083048be24.tar.gz
Merge branch 'ps/reflog-migrate-fixes'
"git refs migrate" to migrate the reflog entries from a refs backend to another had a handful of bugs squashed. * ps/reflog-migrate-fixes: refs: fix invalid old object IDs when migrating reflogs refs: stop unsetting REF_HAVE_OLD for log-only updates refs/files: detect race when generating reflog entry for HEAD refs: fix identity for migrated reflogs ident: fix type of string length parameter builtin/reflog: implement subcommand to write new entries refs: export `ref_transaction_update_reflog()` builtin/reflog: improve grouping of subcommands Documentation/git-reflog: convert to use synopsis type
Diffstat (limited to 'refs')
-rw-r--r--refs/files-backend.c65
-rw-r--r--refs/refs-internal.h3
-rw-r--r--refs/reftable-backend.c26
3 files changed, 77 insertions, 17 deletions
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 088b52c740..dea46d07ae 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -68,6 +68,12 @@
*/
#define REF_DELETED_RMDIR (1 << 9)
+/*
+ * Used to indicate that the reflog-only update has been created via
+ * `split_head_update()`.
+ */
+#define REF_LOG_VIA_SPLIT (1 << 14)
+
struct ref_lock {
char *ref_name;
struct lock_file lk;
@@ -2421,9 +2427,10 @@ static enum ref_transaction_error split_head_update(struct ref_update *update,
new_update = ref_transaction_add_update(
transaction, "HEAD",
- update->flags | REF_LOG_ONLY | REF_NO_DEREF,
+ update->flags | REF_LOG_ONLY | REF_NO_DEREF | REF_LOG_VIA_SPLIT,
&update->new_oid, &update->old_oid,
NULL, NULL, update->committer_info, update->msg);
+ new_update->parent_update = update;
/*
* Add "HEAD". This insertion is O(N) in the transaction
@@ -2494,7 +2501,6 @@ static enum ref_transaction_error split_symref_update(struct ref_update *update,
* done when new_update is processed.
*/
update->flags |= REF_LOG_ONLY | REF_NO_DEREF;
- update->flags &= ~REF_HAVE_OLD;
return 0;
}
@@ -2509,8 +2515,9 @@ static enum ref_transaction_error check_old_oid(struct ref_update *update,
struct object_id *oid,
struct strbuf *err)
{
- if (!(update->flags & REF_HAVE_OLD) ||
- oideq(oid, &update->old_oid))
+ if (update->flags & REF_LOG_ONLY ||
+ !(update->flags & REF_HAVE_OLD) ||
+ oideq(oid, &update->old_oid))
return 0;
if (is_null_oid(&update->old_oid)) {
@@ -2601,7 +2608,36 @@ static enum ref_transaction_error lock_ref_for_update(struct files_ref_store *re
update->backend_data = lock;
- if (update->type & REF_ISSYMREF) {
+ if (update->flags & REF_LOG_VIA_SPLIT) {
+ struct ref_lock *parent_lock;
+
+ if (!update->parent_update)
+ BUG("split update without a parent");
+
+ parent_lock = update->parent_update->backend_data;
+
+ /*
+ * Check that "HEAD" didn't racily change since we have looked
+ * it up. If it did we must refuse to write the reflog entry.
+ *
+ * Note that this does not catch all races: if "HEAD" was
+ * racily changed to point to one of the refs part of the
+ * transaction then we would miss writing the split reflog
+ * entry for "HEAD".
+ */
+ if (!(update->type & REF_ISSYMREF) ||
+ strcmp(update->parent_update->refname, referent.buf)) {
+ strbuf_addstr(err, "HEAD has been racily updated");
+ ret = REF_TRANSACTION_ERROR_GENERIC;
+ goto out;
+ }
+
+ if (update->flags & REF_HAVE_OLD) {
+ oidcpy(&lock->old_oid, &update->old_oid);
+ } else {
+ oidcpy(&lock->old_oid, &parent_lock->old_oid);
+ }
+ } else if (update->type & REF_ISSYMREF) {
if (update->flags & REF_NO_DEREF) {
/*
* We won't be reading the referent as part of
@@ -2977,6 +3013,20 @@ static int parse_and_write_reflog(struct files_ref_store *refs,
struct ref_lock *lock,
struct strbuf *err)
{
+ struct object_id *old_oid = &lock->old_oid;
+
+ if (update->flags & REF_LOG_USE_PROVIDED_OIDS) {
+ if (!(update->flags & REF_HAVE_OLD) ||
+ !(update->flags & REF_HAVE_NEW) ||
+ !(update->flags & REF_LOG_ONLY)) {
+ strbuf_addf(err, _("trying to write reflog for '%s'"
+ "with incomplete values"), update->refname);
+ return REF_TRANSACTION_ERROR_GENERIC;
+ }
+
+ old_oid = &update->old_oid;
+ }
+
if (update->new_target) {
/*
* We want to get the resolved OID for the target, to ensure
@@ -2994,7 +3044,7 @@ static int parse_and_write_reflog(struct files_ref_store *refs,
}
}
- if (files_log_ref_write(refs, lock->ref_name, &lock->old_oid,
+ if (files_log_ref_write(refs, lock->ref_name, old_oid,
&update->new_oid, update->committer_info,
update->msg, update->flags, err)) {
char *old_msg = strbuf_detach(err, NULL);
@@ -3062,7 +3112,8 @@ static int files_transaction_finish_initial(struct files_ref_store *refs,
for (i = 0; i < transaction->nr; i++) {
struct ref_update *update = transaction->updates[i];
- if ((update->flags & REF_HAVE_OLD) &&
+ if (!(update->flags & REF_LOG_ONLY) &&
+ (update->flags & REF_HAVE_OLD) &&
!is_null_oid(&update->old_oid))
BUG("initial ref transaction with old_sha1 set");
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index 40c1c0f93d..54c2079c12 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -662,7 +662,8 @@ enum ref_transaction_error ref_update_check_old_target(const char *referent,
/*
* Check if the ref must exist, this means that the old_oid or
- * old_target is non NULL.
+ * old_target is non NULL. Log-only updates never require the old state to
+ * match.
*/
int ref_update_expects_existing_old_ref(struct ref_update *update);
diff --git a/refs/reftable-backend.c b/refs/reftable-backend.c
index 8dae1e1112..c0440b4bd0 100644
--- a/refs/reftable-backend.c
+++ b/refs/reftable-backend.c
@@ -1102,6 +1102,20 @@ static enum ref_transaction_error prepare_single_update(struct reftable_ref_stor
if (ret)
return REF_TRANSACTION_ERROR_GENERIC;
+ if (u->flags & REF_LOG_USE_PROVIDED_OIDS) {
+ if (!(u->flags & REF_HAVE_OLD) ||
+ !(u->flags & REF_HAVE_NEW) ||
+ !(u->flags & REF_LOG_ONLY)) {
+ strbuf_addf(err, _("trying to write reflog for '%s'"
+ "with incomplete values"), u->refname);
+ return REF_TRANSACTION_ERROR_GENERIC;
+ }
+
+ if (queue_transaction_update(refs, tx_data, u, &u->old_oid, err))
+ return REF_TRANSACTION_ERROR_GENERIC;
+ return 0;
+ }
+
/* Verify that the new object ID is valid. */
if ((u->flags & REF_HAVE_NEW) && !is_null_oid(&u->new_oid) &&
!(u->flags & REF_SKIP_OID_VERIFICATION) &&
@@ -1186,8 +1200,6 @@ static enum ref_transaction_error prepare_single_update(struct reftable_ref_stor
if (ret > 0) {
/* The reference does not exist, but we expected it to. */
strbuf_addf(err, _("cannot lock ref '%s': "
-
-
"unable to resolve reference '%s'"),
ref_update_original_update_refname(u), u->refname);
return REF_TRANSACTION_ERROR_NONEXISTENT_REF;
@@ -1241,13 +1253,8 @@ static enum ref_transaction_error prepare_single_update(struct reftable_ref_stor
new_update->parent_update = u;
- /*
- * Change the symbolic ref update to log only. Also, it
- * doesn't need to check its old OID value, as that will be
- * done when new_update is processed.
- */
+ /* Change the symbolic ref update to log only. */
u->flags |= REF_LOG_ONLY | REF_NO_DEREF;
- u->flags &= ~REF_HAVE_OLD;
}
}
@@ -1271,7 +1278,8 @@ static enum ref_transaction_error prepare_single_update(struct reftable_ref_stor
ret = ref_update_check_old_target(referent->buf, u, err);
if (ret)
return ret;
- } else if ((u->flags & REF_HAVE_OLD) && !oideq(&current_oid, &u->old_oid)) {
+ } else if ((u->flags & (REF_LOG_ONLY | REF_HAVE_OLD)) == REF_HAVE_OLD &&
+ !oideq(&current_oid, &u->old_oid)) {
if (is_null_oid(&u->old_oid)) {
strbuf_addf(err, _("cannot lock ref '%s': "
"reference already exists"),
generated by cgit 1.2.3-korg (git 2.43.0) at 2025-12-09 14:30:45 +0000