From fda0622ea8e2b1781645368d49b98beca50fecba Mon Sep 17 00:00:00 2001
From: Paulo Cabral Sanz <paulo@railway.app>
Date: Fri, 14 Aug 2026 17:37:58 -0300
Subject: [PATCH 1/3] test: compact must fsync the parent directory

artifact::rename_into_place already fsyncs the parent after rename.
compact_to_file is the fold's durable publish and currently does not.
---
 src/snapshot.rs | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/src/snapshot.rs b/src/snapshot.rs
index bd43f8c..d239e4a 100644
--- a/src/snapshot.rs
+++ b/src/snapshot.rs
@@ -1630,4 +1630,25 @@ mod tests {
         );
         assert_eq!(snap.entries["node.a"].value, b"survives");
     }
+
+    /// Compact is the fold's durable publish: inode `sync_all` then rename.
+    /// Without a parent-directory fsync the new dirent can vanish on power
+    /// loss — the same hole `artifact::rename_into_place` already closes.
+    #[test]
+    fn compact_to_file_fsyncs_parent_dirent() {
+        let src = include_str!("snapshot.rs");
+        let compact = src
+            .split("fn compact_to_file(")
+            .nth(1)
+            .expect("compact_to_file must exist");
+        let compact = compact
+            .split("\n// ---------------------------------------------------------------------------")
+            .next()
+            .unwrap();
+        assert!(
+            compact.contains("fsync_dir"),
+            "compact_to_file must fsync the parent directory after persist, \
+             matching artifact::rename_into_place (Pedra F17)"
+        );
+    }
 }

From 3b1fc5609d4fd68a2bf359e05337676ba546a08e Mon Sep 17 00:00:00 2001
From: Paulo Cabral Sanz <paulo@railway.app>
Date: Fri, 14 Aug 2026 17:37:58 -0300
Subject: [PATCH 2/3] fix: fsync parent directory after compact rename

persist() is rename(2). The inode is durable; the new dirent is not
until the parent is fsynced. Reuse artifact::fsync_dir.
---
 src/artifact.rs | 2 +-
 src/snapshot.rs | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/artifact.rs b/src/artifact.rs
index 3df2677..06ec4ac 100644
--- a/src/artifact.rs
+++ b/src/artifact.rs
@@ -360,7 +360,7 @@ pub(crate) fn hash_payload(root: &Path) -> Result<Vec<ArtifactFile>, SnapshotErr
     Ok(files)
 }
 
-fn fsync_dir(path: &Path) -> Result<(), SnapshotError> {
+pub(crate) fn fsync_dir(path: &Path) -> Result<(), SnapshotError> {
     File::open(path)?.sync_all()?;
     Ok(())
 }
diff --git a/src/snapshot.rs b/src/snapshot.rs
index d239e4a..3d5f012 100644
--- a/src/snapshot.rs
+++ b/src/snapshot.rs
@@ -1119,6 +1119,10 @@ fn compact_to_file(
 
     tmp.as_file().sync_all()?;
     tmp.persist(path).map_err(|e| SnapshotError::Io(e.error))?;
+    // persist() is rename(2). The inode is durable; the directory entry is
+    // not until the parent is fsynced. artifact::rename_into_place already
+    // does this — compact is the fold's only other rename-publish.
+    crate::artifact::fsync_dir(dir)?;
 
     Ok(())
 }

From 0fb2ec70ca7e1e077014f44bf8eba6bed40d208e Mon Sep 17 00:00:00 2001
From: Paulo Cabral Sanz <paulo@railway.app>
Date: Fri, 14 Aug 2026 18:07:28 -0300
Subject: [PATCH 3/3] style: rustfmt compact_to_file_fsyncs_parent_dirent

---
 src/snapshot.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/snapshot.rs b/src/snapshot.rs
index 3d5f012..e031d86 100644
--- a/src/snapshot.rs
+++ b/src/snapshot.rs
@@ -1646,7 +1646,9 @@ mod tests {
             .nth(1)
             .expect("compact_to_file must exist");
         let compact = compact
-            .split("\n// ---------------------------------------------------------------------------")
+            .split(
+                "\n// ---------------------------------------------------------------------------",
+            )
             .next()
             .unwrap();
         assert!(