diff --git a/refs.c b/refs.c
index 92d801c00a..46177ad256 100644
--- a/refs.c
+++ b/refs.c
@@ -3237,6 +3237,106 @@ int update_ref(const char *action, const char *refname,
 	return update_ref_write(action, refname, sha1, lock, onerr);
 }
 
+static int ref_update_compare(const void *r1, const void *r2)
+{
+	const struct ref_update * const *u1 = r1;
+	const struct ref_update * const *u2 = r2;
+	return strcmp((*u1)->ref_name, (*u2)->ref_name);
+}
+
+static int ref_update_reject_duplicates(struct ref_update **updates, int n,
+					enum action_on_err onerr)
+{
+	int i;
+	for (i = 1; i < n; i++)
+		if (!strcmp(updates[i - 1]->ref_name, updates[i]->ref_name)) {
+			const char *str =
+				"Multiple updates for ref '%s' not allowed.";
+			switch (onerr) {
+			case MSG_ON_ERR:
+				error(str, updates[i]->ref_name); break;
+			case DIE_ON_ERR:
+				die(str, updates[i]->ref_name); break;
+			case QUIET_ON_ERR:
+				break;
+			}
+			return 1;
+		}
+	return 0;
+}
+
+int update_refs(const char *action, const struct ref_update **updates_orig,
+		int n, enum action_on_err onerr)
+{
+	int ret = 0, delnum = 0, i;
+	struct ref_update **updates;
+	int *types;
+	struct ref_lock **locks;
+	const char **delnames;
+
+	if (!updates_orig || !n)
+		return 0;
+
+	/* Allocate work space */
+	updates = xmalloc(sizeof(*updates) * n);
+	types = xmalloc(sizeof(*types) * n);
+	locks = xcalloc(n, sizeof(*locks));
+	delnames = xmalloc(sizeof(*delnames) * n);
+
+	/* Copy, sort, and reject duplicate refs */
+	memcpy(updates, updates_orig, sizeof(*updates) * n);
+	qsort(updates, n, sizeof(*updates), ref_update_compare);
+	ret = ref_update_reject_duplicates(updates, n, onerr);
+	if (ret)
+		goto cleanup;
+
+	/* Acquire all locks while verifying old values */
+	for (i = 0; i < n; i++) {
+		locks[i] = update_ref_lock(updates[i]->ref_name,
+					   (updates[i]->have_old ?
+					    updates[i]->old_sha1 : NULL),
+					   updates[i]->flags,
+					   &types[i], onerr);
+		if (!locks[i]) {
+			ret = 1;
+			goto cleanup;
+		}
+	}
+
+	/* Perform updates first so live commits remain referenced */
+	for (i = 0; i < n; i++)
+		if (!is_null_sha1(updates[i]->new_sha1)) {
+			ret = update_ref_write(action,
+					       updates[i]->ref_name,
+					       updates[i]->new_sha1,
+					       locks[i], onerr);
+			locks[i] = NULL; /* freed by update_ref_write */
+			if (ret)
+				goto cleanup;
+		}
+
+	/* Perform deletes now that updates are safely completed */
+	for (i = 0; i < n; i++)
+		if (locks[i]) {
+			delnames[delnum++] = locks[i]->ref_name;
+			ret |= delete_ref_loose(locks[i], types[i]);
+		}
+	ret |= repack_without_refs(delnames, delnum);
+	for (i = 0; i < delnum; i++)
+		unlink_or_warn(git_path("logs/%s", delnames[i]));
+	clear_loose_ref_cache(&ref_cache);
+
+cleanup:
+	for (i = 0; i < n; i++)
+		if (locks[i])
+			unlock_ref(locks[i]);
+	free(updates);
+	free(types);
+	free(locks);
+	free(delnames);
+	return ret;
+}
+
 struct ref *find_ref_by_name(const struct ref *list, const char *name)
 {
 	for ( ; list; list = list->next)
diff --git a/refs.h b/refs.h
index 2cd307af25..b113377c48 100644
--- a/refs.h
+++ b/refs.h
@@ -10,6 +10,20 @@ struct ref_lock {
 	int force_write;
 };
 
+/**
+ * Information needed for a single ref update.  Set new_sha1 to the
+ * new value or to zero to delete the ref.  To check the old value
+ * while locking the ref, set have_old to 1 and set old_sha1 to the
+ * value or to zero to ensure the ref does not exist before update.
+ */
+struct ref_update {
+	const char *ref_name;
+	unsigned char new_sha1[20];
+	unsigned char old_sha1[20];
+	int flags; /* REF_NODEREF? */
+	int have_old; /* 1 if old_sha1 is valid, 0 otherwise */
+};
+
 /*
  * Bit values set in the flags argument passed to each_ref_fn():
  */
@@ -214,6 +228,12 @@ int update_ref(const char *action, const char *refname,
 		const unsigned char *sha1, const unsigned char *oldval,
 		int flags, enum action_on_err onerr);
 
+/**
+ * Lock all refs and then perform all modifications.
+ */
+int update_refs(const char *action, const struct ref_update **updates,
+		int n, enum action_on_err onerr);
+
 extern int parse_hide_refs_config(const char *var, const char *value, const char *);
 extern int ref_is_hidden(const char *);