From bd9cd548b02e77fea8e9ba5d03993b1a688ef223 Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@openldap.org>
Date: Wed, 15 Apr 2026 19:39:36 +0100
Subject: [PATCH] ITS#10454 lmdb: can't rely on O_DSYNC on MacOS

So we must explicitly sync writes to the metapage.
---
 libraries/liblmdb/mdb.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 6247f867ab..1c885e8dd6 100644
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -4865,6 +4865,12 @@ mdb_env_write_meta(MDB_txn *txn)
 				rc = ErrCode();
 				goto fail;
 			}
+#if defined(__APPLE__)
+			if (MDB_FDATASYNC(env->me_mfd)) {
+				rc = ErrCode();
+				goto fail;
+			}
+#endif
 		}
 		goto done;
 	}
@@ -4924,6 +4930,12 @@ fail:
 		env->me_flags |= MDB_FATAL_ERROR;
 		return rc;
 	}
+#if defined(__APPLE__)
+	if (mfd == env->me_mfd && MDB_FDATASYNC(env->me_mfd)) {
+		rc = ErrCode();
+		return rc;
+	}
+#endif
 	/* MIPS has cache coherency issues, this is a no-op everywhere else */
 	CACHEFLUSH(env->me_map + off, len, DCACHE);
 done: