Detect nested v1 filesystem data

lightning-persister/src/fs_store/v2.rs

@@ -21,8 +21,8 @@ use std::sync::Arc;
 /// An error returned when constructing a [`FilesystemStoreV2`].
 #[derive(Debug)]
 pub enum FilesystemStoreV2Error {
-	/// The data directory contains a file at the top level, indicating it was previously used
-	/// by [`FilesystemStore`] (v1). Contains the path of the offending file.
+	/// The data directory contains a file where v2 expects a namespace directory, indicating it
+	/// was previously used by [`FilesystemStore`] (v1). Contains the path of the offending file.
 	///
 	/// [`FilesystemStore`]: crate::fs_store::v1::FilesystemStore
 	V1DataDetected(PathBuf),
@@ -35,7 +35,7 @@ impl fmt::Display for FilesystemStoreV2Error {
  match self {
  Self::V1DataDetected(path) => write!(
  f,
- "Found file `{}` in the top-level data directory. \
+ "Found file `{}` where FilesystemStoreV2 expects a namespace directory. \
  This indicates the directory was previously used by FilesystemStore (v1). \
  Please migrate your data or use a different directory.",
  path.display()
@@ -97,18 +97,28 @@ impl FilesystemStoreV2 {
 	/// Constructs a new [`FilesystemStoreV2`].
 	///
 	/// Returns [`FilesystemStoreV2Error::V1DataDetected`] if the data directory already exists
-	/// and contains files at the top level, which would indicate it was previously used by a
-	/// [`FilesystemStore`] (v1). The v2 store expects only directories (namespaces) at the top
-	/// level.
+	/// and contains files where v2 expects namespace directories, which would indicate it was
+	/// previously used by a [`FilesystemStore`] (v1). The v2 store expects only directories at
+	/// the top level and one level down.
 	///
 	/// [`FilesystemStore`]: crate::fs_store::v1::FilesystemStore
 	pub fn new(data_dir: PathBuf) -> Result<Self, FilesystemStoreV2Error> {
  if data_dir.exists() {
  for entry in fs::read_dir(&data_dir)? {
  let entry = entry?;
- if entry.file_type()?.is_file() {
+ let file_type = entry.file_type()?;
+ if file_type.is_file() {
  return Err(FilesystemStoreV2Error::V1DataDetected(entry.path()));
  }
+
+ if file_type.is_dir() {
+ for child_entry in fs::read_dir(entry.path())? {
+ let child_entry = child_entry?;
+ if child_entry.file_type()?.is_file() {
+ return Err(FilesystemStoreV2Error::V1DataDetected(child_entry.path()));
+ }
+ }
+ }
  }
  }
 
@@ -699,6 +709,7 @@ mod tests {
  fs::create_dir_all(&temp_path).unwrap();
 
  // Create a file at the top level, as v1 would for an empty primary namespace
+ // and an empty secondary namespace.
  fs::write(temp_path.join("some_key"), b"data").unwrap();
 
  // V2 construction should fail
@@ -713,13 +724,59 @@ mod tests {
  // Clean up
  let _ = fs::remove_dir_all(&temp_path);
 
+ // Create a file one level down, as v1 would for a non-empty primary namespace
+ // and an empty secondary namespace.
+ fs::create_dir_all(temp_path.join("some_namespace")).unwrap();
+ fs::write(temp_path.join("some_namespace").join("some_key"), b"data").unwrap();
+
+ match FilesystemStoreV2::new(temp_path.clone()) {
+ Err(FilesystemStoreV2Error::V1DataDetected(path)) => {
+ assert_eq!(path, temp_path.join("some_namespace").join("some_key"));
+ },
+ Err(err) => panic!("Expected V1DataDetected, got {:?}", err),
+ Ok(_) => panic!("Expected error for directory with files one level down"),
+ }
+
+ let _ = fs::remove_dir_all(&temp_path);
+
+ // A v1 write with an empty primary namespace and non-empty secondary namespace
+ // is rejected by the KVStore API, but its filesystem layout would be the same
+ // one-level shape.
+ fs::create_dir_all(temp_path.join("some_secondary_namespace")).unwrap();
+ fs::write(temp_path.join("some_secondary_namespace").join("some_key"), b"data").unwrap();
+
+ match FilesystemStoreV2::new(temp_path.clone()) {
+ Err(FilesystemStoreV2Error::V1DataDetected(path)) => {
+ assert_eq!(path, temp_path.join("some_secondary_namespace").join("some_key"));
+ },
+ Err(err) => panic!("Expected V1DataDetected, got {:?}", err),
+ Ok(_) => panic!("Expected error for directory with files one level down"),
+ }
+
+ let _ = fs::remove_dir_all(&temp_path);
+
  // An empty directory should succeed
  fs::create_dir_all(&temp_path).unwrap();
  let result = FilesystemStoreV2::new(temp_path.clone());
  assert!(result.is_ok());
 
- // A directory with only subdirectories should succeed
- fs::create_dir_all(temp_path.join("some_namespace")).unwrap();
+ // A directory with only namespace subdirectories should succeed
+ fs::create_dir_all(temp_path.join("some_namespace").join("some_sub_namespace")).unwrap();
+ let result = FilesystemStoreV2::new(temp_path.clone());
+ assert!(result.is_ok());
+
+ // V1 data with non-empty primary and secondary namespaces has the same filesystem
+ // layout as valid v2 data, so construction must not reject this shape.
+ let fs_store = result.unwrap();
+ KVStoreSync::write(
+ &fs_store,
+ "some_namespace",
+ "some_sub_namespace",
+ "some_key",
+ b"data".to_vec(),
+ )
+ .unwrap();
+
  let result = FilesystemStoreV2::new(temp_path);
  assert!(result.is_ok());
 	}

lightning-persister/src/fs_store/v2.rs

@@ -21,8 +21,8 @@ use std::sync::Arc;
 /// An error returned when constructing a [`FilesystemStoreV2`].
 #[derive(Debug)]
 pub enum FilesystemStoreV2Error {
-	/// The data directory contains a file at the top level, indicating it was previously used
-	/// by [`FilesystemStore`] (v1). Contains the path of the offending file.
+	/// The data directory contains a file where v2 expects a namespace directory, indicating it
+	/// was previously used by [`FilesystemStore`] (v1). Contains the path of the offending file.
 	///
 	/// [`FilesystemStore`]: crate::fs_store::v1::FilesystemStore
 	V1DataDetected(PathBuf),
@@ -35,7 +35,7 @@ impl fmt::Display for FilesystemStoreV2Error {
  match self {
  Self::V1DataDetected(path) => write!(
  f,
- "Found file `{}` in the top-level data directory. \
+ "Found file `{}` where FilesystemStoreV2 expects a namespace directory. \
  This indicates the directory was previously used by FilesystemStore (v1). \
  Please migrate your data or use a different directory.",
  path.display()
@@ -97,18 +97,28 @@ impl FilesystemStoreV2 {
 	/// Constructs a new [`FilesystemStoreV2`].
 	///
 	/// Returns [`FilesystemStoreV2Error::V1DataDetected`] if the data directory already exists
-	/// and contains files at the top level, which would indicate it was previously used by a
-	/// [`FilesystemStore`] (v1). The v2 store expects only directories (namespaces) at the top
-	/// level.
+	/// and contains files where v2 expects namespace directories, which would indicate it was
+	/// previously used by a [`FilesystemStore`] (v1). The v2 store expects only directories at
+	/// the top level and one level down.
 	///
 	/// [`FilesystemStore`]: crate::fs_store::v1::FilesystemStore
 	pub fn new(data_dir: PathBuf) -> Result<Self, FilesystemStoreV2Error> {
  if data_dir.exists() {
  for entry in fs::read_dir(&data_dir)? {
  let entry = entry?;
- if entry.file_type()?.is_file() {
+ let file_type = entry.file_type()?;
+ if file_type.is_file() {
  return Err(FilesystemStoreV2Error::V1DataDetected(entry.path()));
  }
+
+ if file_type.is_dir() {
+ for child_entry in fs::read_dir(entry.path())? {
+ let child_entry = child_entry?;
+ if child_entry.file_type()?.is_file() {
+ return Err(FilesystemStoreV2Error::V1DataDetected(child_entry.path()));
+ }
+ }
+ }
  }
  }
 
@@ -699,6 +709,7 @@ mod tests {
  fs::create_dir_all(&temp_path).unwrap();
 
  // Create a file at the top level, as v1 would for an empty primary namespace
+ // and an empty secondary namespace.
  fs::write(temp_path.join("some_key"), b"data").unwrap();
 
  // V2 construction should fail
@@ -713,13 +724,59 @@ mod tests {
  // Clean up
  let _ = fs::remove_dir_all(&temp_path);
 
+ // Create a file one level down, as v1 would for a non-empty primary namespace
+ // and an empty secondary namespace.
+ fs::create_dir_all(temp_path.join("some_namespace")).unwrap();
+ fs::write(temp_path.join("some_namespace").join("some_key"), b"data").unwrap();
+
+ match FilesystemStoreV2::new(temp_path.clone()) {
+ Err(FilesystemStoreV2Error::V1DataDetected(path)) => {
+ assert_eq!(path, temp_path.join("some_namespace").join("some_key"));
+ },
+ Err(err) => panic!("Expected V1DataDetected, got {:?}", err),
+ Ok(_) => panic!("Expected error for directory with files one level down"),
+ }
+
+ let _ = fs::remove_dir_all(&temp_path);
+
+ // A v1 write with an empty primary namespace and non-empty secondary namespace
+ // is rejected by the KVStore API, but its filesystem layout would be the same
+ // one-level shape.
+ fs::create_dir_all(temp_path.join("some_secondary_namespace")).unwrap();
+ fs::write(temp_path.join("some_secondary_namespace").join("some_key"), b"data").unwrap();
+
+ match FilesystemStoreV2::new(temp_path.clone()) {
+ Err(FilesystemStoreV2Error::V1DataDetected(path)) => {
+ assert_eq!(path, temp_path.join("some_secondary_namespace").join("some_key"));
+ },
+ Err(err) => panic!("Expected V1DataDetected, got {:?}", err),
+ Ok(_) => panic!("Expected error for directory with files one level down"),
+ }
+
+ let _ = fs::remove_dir_all(&temp_path);
+
  // An empty directory should succeed
  fs::create_dir_all(&temp_path).unwrap();
  let result = FilesystemStoreV2::new(temp_path.clone());
  assert!(result.is_ok());
 
- // A directory with only subdirectories should succeed
- fs::create_dir_all(temp_path.join("some_namespace")).unwrap();
+ // A directory with only namespace subdirectories should succeed
+ fs::create_dir_all(temp_path.join("some_namespace").join("some_sub_namespace")).unwrap();
+ let result = FilesystemStoreV2::new(temp_path.clone());
+ assert!(result.is_ok());
+
+ // V1 data with non-empty primary and secondary namespaces has the same filesystem
+ // layout as valid v2 data, so construction must not reject this shape.
+ let fs_store = result.unwrap();
+ KVStoreSync::write(
+ &fs_store,
+ "some_namespace",
+ "some_sub_namespace",
+ "some_key",
+ b"data".to_vec(),
+ )
+ .unwrap();
+
  let result = FilesystemStoreV2::new(temp_path);
  assert!(result.is_ok());
 	}

lightning-persister/src/fs_store/v2.rs

@@ -21,8 +21,8 @@ use std::sync::Arc;
 /// An error returned when constructing a [`FilesystemStoreV2`].
 #[derive(Debug)]
 pub enum FilesystemStoreV2Error {
-	/// The data directory contains a file at the top level, indicating it was previously used
-	/// by [`FilesystemStore`] (v1). Contains the path of the offending file.
+	/// The data directory contains a file where v2 expects a namespace directory, indicating it
+	/// was previously used by [`FilesystemStore`] (v1). Contains the path of the offending file.
 	///
 	/// [`FilesystemStore`]: crate::fs_store::v1::FilesystemStore
 	V1DataDetected(PathBuf),
@@ -35,7 +35,7 @@ impl fmt::Display for FilesystemStoreV2Error {
  match self {
  Self::V1DataDetected(path) => write!(
  f,
- "Found file `{}` in the top-level data directory. \
+ "Found file `{}` where FilesystemStoreV2 expects a namespace directory. \
  This indicates the directory was previously used by FilesystemStore (v1). \
  Please migrate your data or use a different directory.",
  path.display()
@@ -97,18 +97,28 @@ impl FilesystemStoreV2 {
 	/// Constructs a new [`FilesystemStoreV2`].
 	///
 	/// Returns [`FilesystemStoreV2Error::V1DataDetected`] if the data directory already exists
-	/// and contains files at the top level, which would indicate it was previously used by a
-	/// [`FilesystemStore`] (v1). The v2 store expects only directories (namespaces) at the top
-	/// level.
+	/// and contains files where v2 expects namespace directories, which would indicate it was
+	/// previously used by a [`FilesystemStore`] (v1). The v2 store expects only directories at
+	/// the top level and one level down.
 	///
 	/// [`FilesystemStore`]: crate::fs_store::v1::FilesystemStore
 	pub fn new(data_dir: PathBuf) -> Result<Self, FilesystemStoreV2Error> {
  if data_dir.exists() {
  for entry in fs::read_dir(&data_dir)? {
  let entry = entry?;
- if entry.file_type()?.is_file() {
+ let file_type = entry.file_type()?;
+ if file_type.is_file() {
  return Err(FilesystemStoreV2Error::V1DataDetected(entry.path()));
  }
+
+ if file_type.is_dir() {
+ for child_entry in fs::read_dir(entry.path())? {
+ let child_entry = child_entry?;
+ if child_entry.file_type()?.is_file() {
+ return Err(FilesystemStoreV2Error::V1DataDetected(child_entry.path()));
+ }
+ }
+ }
  }
  }
 
@@ -699,6 +709,7 @@ mod tests {
  fs::create_dir_all(&temp_path).unwrap();
 
  // Create a file at the top level, as v1 would for an empty primary namespace
+ // and an empty secondary namespace.
  fs::write(temp_path.join("some_key"), b"data").unwrap();
 
  // V2 construction should fail
@@ -713,13 +724,59 @@ mod tests {
  // Clean up
  let _ = fs::remove_dir_all(&temp_path);
 
+ // Create a file one level down, as v1 would for a non-empty primary namespace
+ // and an empty secondary namespace.
+ fs::create_dir_all(temp_path.join("some_namespace")).unwrap();
+ fs::write(temp_path.join("some_namespace").join("some_key"), b"data").unwrap();
+
+ match FilesystemStoreV2::new(temp_path.clone()) {
+ Err(FilesystemStoreV2Error::V1DataDetected(path)) => {
+ assert_eq!(path, temp_path.join("some_namespace").join("some_key"));
+ },
+ Err(err) => panic!("Expected V1DataDetected, got {:?}", err),
+ Ok(_) => panic!("Expected error for directory with files one level down"),
+ }
+
+ let _ = fs::remove_dir_all(&temp_path);
+
+ // A v1 write with an empty primary namespace and non-empty secondary namespace
+ // is rejected by the KVStore API, but its filesystem layout would be the same
+ // one-level shape.
+ fs::create_dir_all(temp_path.join("some_secondary_namespace")).unwrap();
+ fs::write(temp_path.join("some_secondary_namespace").join("some_key"), b"data").unwrap();
+
+ match FilesystemStoreV2::new(temp_path.clone()) {
+ Err(FilesystemStoreV2Error::V1DataDetected(path)) => {
+ assert_eq!(path, temp_path.join("some_secondary_namespace").join("some_key"));
+ },
+ Err(err) => panic!("Expected V1DataDetected, got {:?}", err),
+ Ok(_) => panic!("Expected error for directory with files one level down"),
+ }
+
+ let _ = fs::remove_dir_all(&temp_path);
+
  // An empty directory should succeed
  fs::create_dir_all(&temp_path).unwrap();
  let result = FilesystemStoreV2::new(temp_path.clone());
  assert!(result.is_ok());
 
- // A directory with only subdirectories should succeed
- fs::create_dir_all(temp_path.join("some_namespace")).unwrap();
+ // A directory with only namespace subdirectories should succeed
+ fs::create_dir_all(temp_path.join("some_namespace").join("some_sub_namespace")).unwrap();
+ let result = FilesystemStoreV2::new(temp_path.clone());
+ assert!(result.is_ok());
+
+ // V1 data with non-empty primary and secondary namespaces has the same filesystem
+ // layout as valid v2 data, so construction must not reject this shape.
+ let fs_store = result.unwrap();
+ KVStoreSync::write(
+ &fs_store,
+ "some_namespace",
+ "some_sub_namespace",
+ "some_key",
+ b"data".to_vec(),
+ )
+ .unwrap();
+
  let result = FilesystemStoreV2::new(temp_path);
  assert!(result.is_ok());
 	}

lightning-persister/src/fs_store/v2.rs

@@ -21,8 +21,8 @@ use std::sync::Arc;
 /// An error returned when constructing a [`FilesystemStoreV2`].
 #[derive(Debug)]
 pub enum FilesystemStoreV2Error {
-	/// The data directory contains a file at the top level, indicating it was previously used
-	/// by [`FilesystemStore`] (v1). Contains the path of the offending file.
+	/// The data directory contains a file where v2 expects a namespace directory, indicating it
+	/// was previously used by [`FilesystemStore`] (v1). Contains the path of the offending file.
 	///
 	/// [`FilesystemStore`]: crate::fs_store::v1::FilesystemStore
 	V1DataDetected(PathBuf),
@@ -35,7 +35,7 @@ impl fmt::Display for FilesystemStoreV2Error {
  match self {
  Self::V1DataDetected(path) => write!(
  f,
- "Found file `{}` in the top-level data directory. \
+ "Found file `{}` where FilesystemStoreV2 expects a namespace directory. \
  This indicates the directory was previously used by FilesystemStore (v1). \
  Please migrate your data or use a different directory.",
  path.display()
@@ -97,18 +97,28 @@ impl FilesystemStoreV2 {
 	/// Constructs a new [`FilesystemStoreV2`].
 	///
 	/// Returns [`FilesystemStoreV2Error::V1DataDetected`] if the data directory already exists
-	/// and contains files at the top level, which would indicate it was previously used by a
-	/// [`FilesystemStore`] (v1). The v2 store expects only directories (namespaces) at the top
-	/// level.
+	/// and contains files where v2 expects namespace directories, which would indicate it was
+	/// previously used by a [`FilesystemStore`] (v1). The v2 store expects only directories at
+	/// the top level and one level down.
 	///
 	/// [`FilesystemStore`]: crate::fs_store::v1::FilesystemStore
 	pub fn new(data_dir: PathBuf) -> Result<Self, FilesystemStoreV2Error> {
  if data_dir.exists() {
  for entry in fs::read_dir(&data_dir)? {
  let entry = entry?;
- if entry.file_type()?.is_file() {
+ let file_type = entry.file_type()?;
+ if file_type.is_file() {
  return Err(FilesystemStoreV2Error::V1DataDetected(entry.path()));
  }
+
+ if file_type.is_dir() {
+ for child_entry in fs::read_dir(entry.path())? {
+ let child_entry = child_entry?;
+ if child_entry.file_type()?.is_file() {
+ return Err(FilesystemStoreV2Error::V1DataDetected(child_entry.path()));
+ }
+ }
+ }
  }
  }
 
@@ -699,6 +709,7 @@ mod tests {
  fs::create_dir_all(&temp_path).unwrap();
 
  // Create a file at the top level, as v1 would for an empty primary namespace
+ // and an empty secondary namespace.
  fs::write(temp_path.join("some_key"), b"data").unwrap();
 
  // V2 construction should fail
@@ -713,13 +724,59 @@ mod tests {
  // Clean up
  let _ = fs::remove_dir_all(&temp_path);
 
+ // Create a file one level down, as v1 would for a non-empty primary namespace
+ // and an empty secondary namespace.
+ fs::create_dir_all(temp_path.join("some_namespace")).unwrap();
+ fs::write(temp_path.join("some_namespace").join("some_key"), b"data").unwrap();
+
+ match FilesystemStoreV2::new(temp_path.clone()) {
+ Err(FilesystemStoreV2Error::V1DataDetected(path)) => {
+ assert_eq!(path, temp_path.join("some_namespace").join("some_key"));
+ },
+ Err(err) => panic!("Expected V1DataDetected, got {:?}", err),
+ Ok(_) => panic!("Expected error for directory with files one level down"),
+ }
+
+ let _ = fs::remove_dir_all(&temp_path);
+
+ // A v1 write with an empty primary namespace and non-empty secondary namespace
+ // is rejected by the KVStore API, but its filesystem layout would be the same
+ // one-level shape.
+ fs::create_dir_all(temp_path.join("some_secondary_namespace")).unwrap();
+ fs::write(temp_path.join("some_secondary_namespace").join("some_key"), b"data").unwrap();
+
+ match FilesystemStoreV2::new(temp_path.clone()) {
+ Err(FilesystemStoreV2Error::V1DataDetected(path)) => {
+ assert_eq!(path, temp_path.join("some_secondary_namespace").join("some_key"));
+ },
+ Err(err) => panic!("Expected V1DataDetected, got {:?}", err),
+ Ok(_) => panic!("Expected error for directory with files one level down"),
+ }
+
+ let _ = fs::remove_dir_all(&temp_path);
+
  // An empty directory should succeed
  fs::create_dir_all(&temp_path).unwrap();
  let result = FilesystemStoreV2::new(temp_path.clone());
  assert!(result.is_ok());
 
- // A directory with only subdirectories should succeed
- fs::create_dir_all(temp_path.join("some_namespace")).unwrap();
+ // A directory with only namespace subdirectories should succeed
+ fs::create_dir_all(temp_path.join("some_namespace").join("some_sub_namespace")).unwrap();
+ let result = FilesystemStoreV2::new(temp_path.clone());
+ assert!(result.is_ok());
+
+ // V1 data with non-empty primary and secondary namespaces has the same filesystem
+ // layout as valid v2 data, so construction must not reject this shape.
+ let fs_store = result.unwrap();
+ KVStoreSync::write(
+ &fs_store,
+ "some_namespace",
+ "some_sub_namespace",
+ "some_key",
+ b"data".to_vec(),
+ )
+ .unwrap();
+
  let result = FilesystemStoreV2::new(temp_path);
  assert!(result.is_ok());
 	}

lightning-persister/src/fs_store/v2.rs

@@ -21,8 +21,8 @@ use std::sync::Arc;
 /// An error returned when constructing a [`FilesystemStoreV2`].
 #[derive(Debug)]
 pub enum FilesystemStoreV2Error {
-	/// The data directory contains a file at the top level, indicating it was previously used
-	/// by [`FilesystemStore`] (v1). Contains the path of the offending file.
+	/// The data directory contains a file where v2 expects a namespace directory, indicating it
+	/// was previously used by [`FilesystemStore`] (v1). Contains the path of the offending file.
 	///
 	/// [`FilesystemStore`]: crate::fs_store::v1::FilesystemStore
 	V1DataDetected(PathBuf),
@@ -35,7 +35,7 @@ impl fmt::Display for FilesystemStoreV2Error {
  match self {
  Self::V1DataDetected(path) => write!(
  f,
- "Found file `{}` in the top-level data directory. \
+ "Found file `{}` where FilesystemStoreV2 expects a namespace directory. \
  This indicates the directory was previously used by FilesystemStore (v1). \
  Please migrate your data or use a different directory.",
  path.display()
@@ -97,18 +97,28 @@ impl FilesystemStoreV2 {
 	/// Constructs a new [`FilesystemStoreV2`].
 	///
 	/// Returns [`FilesystemStoreV2Error::V1DataDetected`] if the data directory already exists
-	/// and contains files at the top level, which would indicate it was previously used by a
-	/// [`FilesystemStore`] (v1). The v2 store expects only directories (namespaces) at the top
-	/// level.
+	/// and contains files where v2 expects namespace directories, which would indicate it was
+	/// previously used by a [`FilesystemStore`] (v1). The v2 store expects only directories at
+	/// the top level and one level down.
 	///
 	/// [`FilesystemStore`]: crate::fs_store::v1::FilesystemStore
 	pub fn new(data_dir: PathBuf) -> Result<Self, FilesystemStoreV2Error> {
  if data_dir.exists() {
  for entry in fs::read_dir(&data_dir)? {
  let entry = entry?;
- if entry.file_type()?.is_file() {
+ let file_type = entry.file_type()?;
+ if file_type.is_file() {
  return Err(FilesystemStoreV2Error::V1DataDetected(entry.path()));
  }
+
+ if file_type.is_dir() {
+ for child_entry in fs::read_dir(entry.path())? {
+ let child_entry = child_entry?;
+ if child_entry.file_type()?.is_file() {
+ return Err(FilesystemStoreV2Error::V1DataDetected(child_entry.path()));
+ }
+ }
+ }
  }
  }
 
@@ -699,6 +709,7 @@ mod tests {
  fs::create_dir_all(&temp_path).unwrap();
 
  // Create a file at the top level, as v1 would for an empty primary namespace
+ // and an empty secondary namespace.
  fs::write(temp_path.join("some_key"), b"data").unwrap();
 
  // V2 construction should fail
@@ -713,13 +724,59 @@ mod tests {
  // Clean up
  let _ = fs::remove_dir_all(&temp_path);
 
+ // Create a file one level down, as v1 would for a non-empty primary namespace
+ // and an empty secondary namespace.
+ fs::create_dir_all(temp_path.join("some_namespace")).unwrap();
+ fs::write(temp_path.join("some_namespace").join("some_key"), b"data").unwrap();
+
+ match FilesystemStoreV2::new(temp_path.clone()) {
+ Err(FilesystemStoreV2Error::V1DataDetected(path)) => {
+ assert_eq!(path, temp_path.join("some_namespace").join("some_key"));
+ },
+ Err(err) => panic!("Expected V1DataDetected, got {:?}", err),
+ Ok(_) => panic!("Expected error for directory with files one level down"),
+ }
+
+ let _ = fs::remove_dir_all(&temp_path);
+
+ // A v1 write with an empty primary namespace and non-empty secondary namespace
+ // is rejected by the KVStore API, but its filesystem layout would be the same
+ // one-level shape.
+ fs::create_dir_all(temp_path.join("some_secondary_namespace")).unwrap();
+ fs::write(temp_path.join("some_secondary_namespace").join("some_key"), b"data").unwrap();
+
+ match FilesystemStoreV2::new(temp_path.clone()) {
+ Err(FilesystemStoreV2Error::V1DataDetected(path)) => {
+ assert_eq!(path, temp_path.join("some_secondary_namespace").join("some_key"));
+ },
+ Err(err) => panic!("Expected V1DataDetected, got {:?}", err),
+ Ok(_) => panic!("Expected error for directory with files one level down"),
+ }
+
+ let _ = fs::remove_dir_all(&temp_path);
+
  // An empty directory should succeed
  fs::create_dir_all(&temp_path).unwrap();
  let result = FilesystemStoreV2::new(temp_path.clone());
  assert!(result.is_ok());
 
- // A directory with only subdirectories should succeed
- fs::create_dir_all(temp_path.join("some_namespace")).unwrap();
+ // A directory with only namespace subdirectories should succeed
+ fs::create_dir_all(temp_path.join("some_namespace").join("some_sub_namespace")).unwrap();
+ let result = FilesystemStoreV2::new(temp_path.clone());
+ assert!(result.is_ok());
+
+ // V1 data with non-empty primary and secondary namespaces has the same filesystem
+ // layout as valid v2 data, so construction must not reject this shape.
+ let fs_store = result.unwrap();
+ KVStoreSync::write(
+ &fs_store,
+ "some_namespace",
+ "some_sub_namespace",
+ "some_key",
+ b"data".to_vec(),
+ )
+ .unwrap();
+
  let result = FilesystemStoreV2::new(temp_path);
  assert!(result.is_ok());
 	}

lightning-persister/src/fs_store/v2.rs

@@ -21,8 +21,8 @@ use std::sync::Arc;
 /// An error returned when constructing a [`FilesystemStoreV2`].
 #[derive(Debug)]
 pub enum FilesystemStoreV2Error {
-	/// The data directory contains a file at the top level, indicating it was previously used
-	/// by [`FilesystemStore`] (v1). Contains the path of the offending file.
+	/// The data directory contains a file where v2 expects a namespace directory, indicating it
+	/// was previously used by [`FilesystemStore`] (v1). Contains the path of the offending file.
 	///
 	/// [`FilesystemStore`]: crate::fs_store::v1::FilesystemStore
 	V1DataDetected(PathBuf),
@@ -35,7 +35,7 @@ impl fmt::Display for FilesystemStoreV2Error {
  match self {
  Self::V1DataDetected(path) => write!(
  f,
- "Found file `{}` in the top-level data directory. \
+ "Found file `{}` where FilesystemStoreV2 expects a namespace directory. \
  This indicates the directory was previously used by FilesystemStore (v1). \
  Please migrate your data or use a different directory.",
  path.display()
@@ -97,18 +97,28 @@ impl FilesystemStoreV2 {
 	/// Constructs a new [`FilesystemStoreV2`].
 	///
 	/// Returns [`FilesystemStoreV2Error::V1DataDetected`] if the data directory already exists
-	/// and contains files at the top level, which would indicate it was previously used by a
-	/// [`FilesystemStore`] (v1). The v2 store expects only directories (namespaces) at the top
-	/// level.
+	/// and contains files where v2 expects namespace directories, which would indicate it was
+	/// previously used by a [`FilesystemStore`] (v1). The v2 store expects only directories at
+	/// the top level and one level down.
 	///
 	/// [`FilesystemStore`]: crate::fs_store::v1::FilesystemStore
 	pub fn new(data_dir: PathBuf) -> Result<Self, FilesystemStoreV2Error> {
  if data_dir.exists() {
  for entry in fs::read_dir(&data_dir)? {
  let entry = entry?;
- if entry.file_type()?.is_file() {
+ let file_type = entry.file_type()?;
+ if file_type.is_file() {
  return Err(FilesystemStoreV2Error::V1DataDetected(entry.path()));
  }
+
+ if file_type.is_dir() {
+ for child_entry in fs::read_dir(entry.path())? {
+ let child_entry = child_entry?;
+ if child_entry.file_type()?.is_file() {
+ return Err(FilesystemStoreV2Error::V1DataDetected(child_entry.path()));
+ }
+ }
+ }
  }
  }
 
@@ -699,6 +709,7 @@ mod tests {
  fs::create_dir_all(&temp_path).unwrap();
 
  // Create a file at the top level, as v1 would for an empty primary namespace
+ // and an empty secondary namespace.
  fs::write(temp_path.join("some_key"), b"data").unwrap();
 
  // V2 construction should fail
@@ -713,13 +724,59 @@ mod tests {
  // Clean up
  let _ = fs::remove_dir_all(&temp_path);
 
+ // Create a file one level down, as v1 would for a non-empty primary namespace
+ // and an empty secondary namespace.
+ fs::create_dir_all(temp_path.join("some_namespace")).unwrap();
+ fs::write(temp_path.join("some_namespace").join("some_key"), b"data").unwrap();
+
+ match FilesystemStoreV2::new(temp_path.clone()) {
+ Err(FilesystemStoreV2Error::V1DataDetected(path)) => {
+ assert_eq!(path, temp_path.join("some_namespace").join("some_key"));
+ },
+ Err(err) => panic!("Expected V1DataDetected, got {:?}", err),
+ Ok(_) => panic!("Expected error for directory with files one level down"),
+ }
+
+ let _ = fs::remove_dir_all(&temp_path);
+
+ // A v1 write with an empty primary namespace and non-empty secondary namespace
+ // is rejected by the KVStore API, but its filesystem layout would be the same
+ // one-level shape.
+ fs::create_dir_all(temp_path.join("some_secondary_namespace")).unwrap();
+ fs::write(temp_path.join("some_secondary_namespace").join("some_key"), b"data").unwrap();
+
+ match FilesystemStoreV2::new(temp_path.clone()) {
+ Err(FilesystemStoreV2Error::V1DataDetected(path)) => {
+ assert_eq!(path, temp_path.join("some_secondary_namespace").join("some_key"));
+ },
+ Err(err) => panic!("Expected V1DataDetected, got {:?}", err),
+ Ok(_) => panic!("Expected error for directory with files one level down"),
+ }
+
+ let _ = fs::remove_dir_all(&temp_path);
+
  // An empty directory should succeed
  fs::create_dir_all(&temp_path).unwrap();
  let result = FilesystemStoreV2::new(temp_path.clone());
  assert!(result.is_ok());
 
- // A directory with only subdirectories should succeed
- fs::create_dir_all(temp_path.join("some_namespace")).unwrap();
+ // A directory with only namespace subdirectories should succeed
+ fs::create_dir_all(temp_path.join("some_namespace").join("some_sub_namespace")).unwrap();
+ let result = FilesystemStoreV2::new(temp_path.clone());
+ assert!(result.is_ok());
+
+ // V1 data with non-empty primary and secondary namespaces has the same filesystem
+ // layout as valid v2 data, so construction must not reject this shape.
+ let fs_store = result.unwrap();
+ KVStoreSync::write(
+ &fs_store,
+ "some_namespace",
+ "some_sub_namespace",
+ "some_key",
+ b"data".to_vec(),
+ )
+ .unwrap();
+
  let result = FilesystemStoreV2::new(temp_path);
  assert!(result.is_ok());
 	}

lightning-persister/src/fs_store/v2.rs

@@ -21,8 +21,8 @@ use std::sync::Arc;
 /// An error returned when constructing a [`FilesystemStoreV2`].
 #[derive(Debug)]
 pub enum FilesystemStoreV2Error {
-	/// The data directory contains a file at the top level, indicating it was previously used
-	/// by [`FilesystemStore`] (v1). Contains the path of the offending file.
+	/// The data directory contains a file where v2 expects a namespace directory, indicating it
+	/// was previously used by [`FilesystemStore`] (v1). Contains the path of the offending file.
 	///
 	/// [`FilesystemStore`]: crate::fs_store::v1::FilesystemStore
 	V1DataDetected(PathBuf),
@@ -35,7 +35,7 @@ impl fmt::Display for FilesystemStoreV2Error {
  match self {
  Self::V1DataDetected(path) => write!(
  f,
- "Found file `{}` in the top-level data directory. \
+ "Found file `{}` where FilesystemStoreV2 expects a namespace directory. \
  This indicates the directory was previously used by FilesystemStore (v1). \
  Please migrate your data or use a different directory.",
  path.display()
@@ -97,18 +97,28 @@ impl FilesystemStoreV2 {
 	/// Constructs a new [`FilesystemStoreV2`].
 	///
 	/// Returns [`FilesystemStoreV2Error::V1DataDetected`] if the data directory already exists
-	/// and contains files at the top level, which would indicate it was previously used by a
-	/// [`FilesystemStore`] (v1). The v2 store expects only directories (namespaces) at the top
-	/// level.
+	/// and contains files where v2 expects namespace directories, which would indicate it was
+	/// previously used by a [`FilesystemStore`] (v1). The v2 store expects only directories at
+	/// the top level and one level down.
 	///
 	/// [`FilesystemStore`]: crate::fs_store::v1::FilesystemStore
 	pub fn new(data_dir: PathBuf) -> Result<Self, FilesystemStoreV2Error> {
  if data_dir.exists() {
  for entry in fs::read_dir(&data_dir)? {
  let entry = entry?;
- if entry.file_type()?.is_file() {
+ let file_type = entry.file_type()?;
+ if file_type.is_file() {
  return Err(FilesystemStoreV2Error::V1DataDetected(entry.path()));
  }
+
+ if file_type.is_dir() {
+ for child_entry in fs::read_dir(entry.path())? {
+ let child_entry = child_entry?;
+ if child_entry.file_type()?.is_file() {
+ return Err(FilesystemStoreV2Error::V1DataDetected(child_entry.path()));
+ }
+ }
+ }
  }
  }
 
@@ -699,6 +709,7 @@ mod tests {
  fs::create_dir_all(&temp_path).unwrap();
 
  // Create a file at the top level, as v1 would for an empty primary namespace
+ // and an empty secondary namespace.
  fs::write(temp_path.join("some_key"), b"data").unwrap();
 
  // V2 construction should fail
@@ -713,13 +724,59 @@ mod tests {
  // Clean up
  let _ = fs::remove_dir_all(&temp_path);
 
+ // Create a file one level down, as v1 would for a non-empty primary namespace
+ // and an empty secondary namespace.
+ fs::create_dir_all(temp_path.join("some_namespace")).unwrap();
+ fs::write(temp_path.join("some_namespace").join("some_key"), b"data").unwrap();
+
+ match FilesystemStoreV2::new(temp_path.clone()) {
+ Err(FilesystemStoreV2Error::V1DataDetected(path)) => {
+ assert_eq!(path, temp_path.join("some_namespace").join("some_key"));
+ },
+ Err(err) => panic!("Expected V1DataDetected, got {:?}", err),
+ Ok(_) => panic!("Expected error for directory with files one level down"),
+ }
+
+ let _ = fs::remove_dir_all(&temp_path);
+
+ // A v1 write with an empty primary namespace and non-empty secondary namespace
+ // is rejected by the KVStore API, but its filesystem layout would be the same
+ // one-level shape.
+ fs::create_dir_all(temp_path.join("some_secondary_namespace")).unwrap();
+ fs::write(temp_path.join("some_secondary_namespace").join("some_key"), b"data").unwrap();
+
+ match FilesystemStoreV2::new(temp_path.clone()) {
+ Err(FilesystemStoreV2Error::V1DataDetected(path)) => {
+ assert_eq!(path, temp_path.join("some_secondary_namespace").join("some_key"));
+ },
+ Err(err) => panic!("Expected V1DataDetected, got {:?}", err),
+ Ok(_) => panic!("Expected error for directory with files one level down"),
+ }
+
+ let _ = fs::remove_dir_all(&temp_path);
+
  // An empty directory should succeed
  fs::create_dir_all(&temp_path).unwrap();
  let result = FilesystemStoreV2::new(temp_path.clone());
  assert!(result.is_ok());
 
- // A directory with only subdirectories should succeed
- fs::create_dir_all(temp_path.join("some_namespace")).unwrap();
+ // A directory with only namespace subdirectories should succeed
+ fs::create_dir_all(temp_path.join("some_namespace").join("some_sub_namespace")).unwrap();
+ let result = FilesystemStoreV2::new(temp_path.clone());
+ assert!(result.is_ok());
+
+ // V1 data with non-empty primary and secondary namespaces has the same filesystem
+ // layout as valid v2 data, so construction must not reject this shape.
+ let fs_store = result.unwrap();
+ KVStoreSync::write(
+ &fs_store,
+ "some_namespace",
+ "some_sub_namespace",
+ "some_key",
+ b"data".to_vec(),
+ )
+ .unwrap();
+
  let result = FilesystemStoreV2::new(temp_path);
  assert!(result.is_ok());
 	}

lightning-persister/src/fs_store/v2.rs

@@ -21,8 +21,8 @@ use std::sync::Arc;
 /// An error returned when constructing a [`FilesystemStoreV2`].
 #[derive(Debug)]
 pub enum FilesystemStoreV2Error {
-	/// The data directory contains a file at the top level, indicating it was previously used
-	/// by [`FilesystemStore`] (v1). Contains the path of the offending file.
+	/// The data directory contains a file where v2 expects a namespace directory, indicating it
+	/// was previously used by [`FilesystemStore`] (v1). Contains the path of the offending file.
 	///
 	/// [`FilesystemStore`]: crate::fs_store::v1::FilesystemStore
 	V1DataDetected(PathBuf),
@@ -35,7 +35,7 @@ impl fmt::Display for FilesystemStoreV2Error {
  match self {
  Self::V1DataDetected(path) => write!(
  f,
- "Found file `{}` in the top-level data directory. \
+ "Found file `{}` where FilesystemStoreV2 expects a namespace directory. \
  This indicates the directory was previously used by FilesystemStore (v1). \
  Please migrate your data or use a different directory.",
  path.display()
@@ -97,18 +97,28 @@ impl FilesystemStoreV2 {
 	/// Constructs a new [`FilesystemStoreV2`].
 	///
 	/// Returns [`FilesystemStoreV2Error::V1DataDetected`] if the data directory already exists
-	/// and contains files at the top level, which would indicate it was previously used by a
-	/// [`FilesystemStore`] (v1). The v2 store expects only directories (namespaces) at the top
-	/// level.
+	/// and contains files where v2 expects namespace directories, which would indicate it was
+	/// previously used by a [`FilesystemStore`] (v1). The v2 store expects only directories at
+	/// the top level and one level down.
 	///
 	/// [`FilesystemStore`]: crate::fs_store::v1::FilesystemStore
 	pub fn new(data_dir: PathBuf) -> Result<Self, FilesystemStoreV2Error> {
  if data_dir.exists() {
  for entry in fs::read_dir(&data_dir)? {
  let entry = entry?;
- if entry.file_type()?.is_file() {
+ let file_type = entry.file_type()?;
+ if file_type.is_file() {
  return Err(FilesystemStoreV2Error::V1DataDetected(entry.path()));
  }
+
+ if file_type.is_dir() {
+ for child_entry in fs::read_dir(entry.path())? {
+ let child_entry = child_entry?;
+ if child_entry.file_type()?.is_file() {
+ return Err(FilesystemStoreV2Error::V1DataDetected(child_entry.path()));
+ }
+ }
+ }
  }
  }
 
@@ -699,6 +709,7 @@ mod tests {
  fs::create_dir_all(&temp_path).unwrap();
 
  // Create a file at the top level, as v1 would for an empty primary namespace
+ // and an empty secondary namespace.
  fs::write(temp_path.join("some_key"), b"data").unwrap();
 
  // V2 construction should fail
@@ -713,13 +724,59 @@ mod tests {
  // Clean up
  let _ = fs::remove_dir_all(&temp_path);
 
+ // Create a file one level down, as v1 would for a non-empty primary namespace
+ // and an empty secondary namespace.
+ fs::create_dir_all(temp_path.join("some_namespace")).unwrap();
+ fs::write(temp_path.join("some_namespace").join("some_key"), b"data").unwrap();
+
+ match FilesystemStoreV2::new(temp_path.clone()) {
+ Err(FilesystemStoreV2Error::V1DataDetected(path)) => {
+ assert_eq!(path, temp_path.join("some_namespace").join("some_key"));
+ },
+ Err(err) => panic!("Expected V1DataDetected, got {:?}", err),
+ Ok(_) => panic!("Expected error for directory with files one level down"),
+ }
+
+ let _ = fs::remove_dir_all(&temp_path);
+
+ // A v1 write with an empty primary namespace and non-empty secondary namespace
+ // is rejected by the KVStore API, but its filesystem layout would be the same
+ // one-level shape.
+ fs::create_dir_all(temp_path.join("some_secondary_namespace")).unwrap();
+ fs::write(temp_path.join("some_secondary_namespace").join("some_key"), b"data").unwrap();
+
+ match FilesystemStoreV2::new(temp_path.clone()) {
+ Err(FilesystemStoreV2Error::V1DataDetected(path)) => {
+ assert_eq!(path, temp_path.join("some_secondary_namespace").join("some_key"));
+ },
+ Err(err) => panic!("Expected V1DataDetected, got {:?}", err),
+ Ok(_) => panic!("Expected error for directory with files one level down"),
+ }
+
+ let _ = fs::remove_dir_all(&temp_path);
+
  // An empty directory should succeed
  fs::create_dir_all(&temp_path).unwrap();
  let result = FilesystemStoreV2::new(temp_path.clone());
  assert!(result.is_ok());
 
- // A directory with only subdirectories should succeed
- fs::create_dir_all(temp_path.join("some_namespace")).unwrap();
+ // A directory with only namespace subdirectories should succeed
+ fs::create_dir_all(temp_path.join("some_namespace").join("some_sub_namespace")).unwrap();
+ let result = FilesystemStoreV2::new(temp_path.clone());
+ assert!(result.is_ok());
+
+ // V1 data with non-empty primary and secondary namespaces has the same filesystem
+ // layout as valid v2 data, so construction must not reject this shape.
+ let fs_store = result.unwrap();
+ KVStoreSync::write(
+ &fs_store,
+ "some_namespace",
+ "some_sub_namespace",
+ "some_key",
+ b"data".to_vec(),
+ )
+ .unwrap();
+
  let result = FilesystemStoreV2::new(temp_path);
  assert!(result.is_ok());
 	}