Fsync directory while persisting AOF manifest, RDB file, and config file (#10737)

The current process to persist files is `write` the data, `fsync` and `rename` the file,
but a underlying problem is that the rename may be lost when a sudden crash like
power outage and the directory hasn't been persisted.

The article [Ensuring data reaches disk](https://lwn.net/Articles/457667/) mentions
a safe way to update file should be:

1. create a new temp file (on the same file system!)
2. write data to the temp file
3. fsync() the temp file
4. rename the temp file to the appropriate name
5. fsync() the containing directory

This commit handles CONFIG REWRITE, AOF manifest, and RDB file (both for persistence,
and the one the replica gets from the master).
It doesn't handle (yet), ACL SAVE and Cluster configs, since these don't yet follow this pattern.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/aof.c b/src/aof.c
index 823759f24..55d9990bc 100644
--- a/src/aof.c
+++ b/src/aof.c
@@ -572,6 +572,16 @@ int writeAofManifestFile(sds buf) {
             tmp_am_name, am_name, strerror(errno));
 
         ret = C_ERR;
+        goto cleanup;
+    }
+
+    /* Also sync the AOF directory as new AOF files may be added in the directory */
+    if (fsyncFileDir(am_filepath) == -1) {
+        serverLog(LL_WARNING, "Fail to fsync AOF directory %s: %s.",
+            am_filepath, strerror(errno));
+
+        ret = C_ERR;
+        goto cleanup;
     }
 
 cleanup: