add comments and extend support of meta information

- add functions to determine the file type and the file size

src/fd/mod.rs

@@ -83,7 +83,7 @@ bitflags! {
 	#[derive(Debug, Copy, Clone)]
 	pub struct AccessPermission: u32 {
 		const S_IFMT = 0o170000;
-		const S_IFSOCK = 0140000;
+		const S_IFSOCK = 0o140000;
 		const S_IFLNK = 0o120000;
 		const S_IFREG = 0o100000;
 		const S_IFBLK = 0o060000;

src/fs/fuse.rs

@@ -187,20 +187,32 @@ unsafe impl FuseOut for fuse_entry_out {}
 #[repr(C)]
 #[derive(Default, Debug)]
 struct fuse_attr {
+	/// inode number
 	pub ino: u64,
+	/// size in bytes
 	pub size: u64,
+	/// size in blocks
 	pub blocks: u64,
+	/// time of last access
 	pub atime: u64,
+	/// time of last modification
 	pub mtime: u64,
+	/// time of last status change
 	pub ctime: u64,
 	pub atimensec: u32,
 	pub mtimensec: u32,
 	pub ctimensec: u32,
+	/// access permissions
 	pub mode: u32,
+	/// number of hard links
 	pub nlink: u32,
+	/// user id
 	pub uid: u32,
+	/// group id
 	pub gid: u32,
+	/// device id
 	pub rdev: u32,
+	/// block size
 	pub blksize: u32,
 	pub padding: u32,
 }

src/fs/mem.rs

@@ -148,7 +148,7 @@ impl Clone for RamFileInterface {
 	}
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug)]
 pub(crate) struct RomFile {
 	data: Arc<RwSpinLock<&'static [u8]>>,
 	attr: FileAttr,
@@ -171,15 +171,15 @@ impl VfsNode for RomFile {
 
 	fn traverse_lstat(&self, components: &mut Vec<&str>) -> Result<FileAttr, IoError> {
 		if components.is_empty() {
-			Ok(self.attr)
+			self.get_file_attributes()
 		} else {
 			Err(IoError::EBADF)
 		}
 	}
 
 	fn traverse_stat(&self, components: &mut Vec<&str>) -> Result<FileAttr, IoError> {
 		if components.is_empty() {
-			Ok(self.attr)
+			self.get_file_attributes()
 		} else {
 			Err(IoError::EBADF)
 		}
@@ -193,7 +193,7 @@ impl RomFile {
 				slice::from_raw_parts(ptr, length)
 			})),
 			attr: FileAttr {
-				st_mode: mode,
+				st_mode: mode | AccessPermission::S_IFREG,
 				..Default::default()
 			},
 		}
@@ -223,15 +223,15 @@ impl VfsNode for RamFile {
 
 	fn traverse_lstat(&self, components: &mut Vec<&str>) -> Result<FileAttr, IoError> {
 		if components.is_empty() {
-			Ok(self.attr)
+			self.get_file_attributes()
 		} else {
 			Err(IoError::EBADF)
 		}
 	}
 
 	fn traverse_stat(&self, components: &mut Vec<&str>) -> Result<FileAttr, IoError> {
 		if components.is_empty() {
-			Ok(self.attr)
+			self.get_file_attributes()
 		} else {
 			Err(IoError::EBADF)
 		}
@@ -243,7 +243,7 @@ impl RamFile {
 		Self {
 			data: Arc::new(RwSpinLock::new(Vec::new())),
 			attr: FileAttr {
-				st_mode: mode,
+				st_mode: mode | AccessPermission::S_IFREG,
 				..Default::default()
 			},
 		}
@@ -263,7 +263,7 @@ impl MemDirectory {
 		Self {
 			inner: Arc::new(RwSpinLock::new(BTreeMap::new())),
 			attr: FileAttr {
-				st_mode: mode,
+				st_mode: mode | AccessPermission::S_IFDIR,
 				..Default::default()
 			},
 		}
@@ -392,7 +392,7 @@ impl VfsNode for MemDirectory {
 
 			if components.is_empty() {
 				if let Some(node) = self.inner.read().get(&node_name) {
-					node.get_file_attributes()?;
+					return node.get_file_attributes();
 				}
 			}
 
@@ -412,7 +412,7 @@ impl VfsNode for MemDirectory {
 
 			if components.is_empty() {
 				if let Some(node) = self.inner.read().get(&node_name) {
-					node.get_file_attributes()?;
+					return node.get_file_attributes();
 				}
 			}
 

src/fs/mod.rs

@@ -307,17 +307,27 @@ pub struct FileAttr {
 	pub st_dev: u64,
 	pub st_ino: u64,
 	pub st_nlink: u64,
+	/// access permissions
 	pub st_mode: AccessPermission,
+	/// user id
 	pub st_uid: u32,
+	/// group id
 	pub st_gid: u32,
+	/// device id
 	pub st_rdev: u64,
+	/// size in bytes
 	pub st_size: i64,
+	/// block size
 	pub st_blksize: i64,
+	/// size in blocks
 	pub st_blocks: i64,
+	/// time of last access
 	pub st_atime: i64,
 	pub st_atime_nsec: i64,
+	/// time of last modification
 	pub st_mtime: i64,
 	pub st_mtime_nsec: i64,
+	/// time of last status change
 	pub st_ctime: i64,
 	pub st_ctime_nsec: i64,
 }
@@ -410,18 +420,30 @@ pub fn file_attributes(path: &str) -> Result<FileAttr, IoError> {
 	FILESYSTEM.get().unwrap().lstat(path)
 }
 
+#[allow(clippy::len_without_is_empty)]
 #[derive(Debug, Copy, Clone)]
 pub struct Metadata(FileAttr);
 
 impl Metadata {
-	pub fn new(attr: FileAttr) -> Self {
-		Self(attr)
-	}
-
 	/// Returns the size of the file, in bytes
 	pub fn len(&self) -> usize {
 		self.0.st_size.try_into().unwrap()
 	}
+
+	/// Returns true if this metadata is for a file.
+	pub fn is_file(&self) -> bool {
+		self.0.st_mode.contains(AccessPermission::S_IFREG)
+	}
+
+	/// Returns true if this metadata is for a directory.
+	pub fn is_dir(&self) -> bool {
+		self.0.st_mode.contains(AccessPermission::S_IFDIR)
+	}
+}
+
+/// Given a path, query the file system to get information about a file, directory, etc.
+pub fn metadata(path: &str) -> Result<Metadata, IoError> {
+	Ok(Metadata(file_attributes(path)?))
 }
 
 #[derive(Debug)]
@@ -464,7 +486,7 @@ impl File {
 	}
 
 	pub fn metadata(&self) -> Result<Metadata, IoError> {
-		Ok(Metadata::new(file_attributes(&self.path)?))
+		metadata(&self.path)
 	}
 }