Add comments in ch6

easy-fs/src/efs.rs

@@ -5,18 +5,22 @@ use super::{
 use crate::BLOCK_SZ;
 use alloc::sync::Arc;
 use spin::Mutex;
-
+///An easy file system on block
 pub struct EasyFileSystem {
+    ///Real device
     pub block_device: Arc<dyn BlockDevice>,
+    ///Inode bitmap
     pub inode_bitmap: Bitmap,
+    ///Data bitmap
     pub data_bitmap: Bitmap,
     inode_area_start_block: u32,
     data_area_start_block: u32,
 }
 
 type DataBlock = [u8; BLOCK_SZ];
-
+/// An easy fs over a block device
 impl EasyFileSystem {
+    /// A data block of block size
     pub fn create(
         block_device: Arc<dyn BlockDevice>,
         total_blocks: u32,
@@ -77,7 +81,7 @@ impl EasyFileSystem {
         block_cache_sync_all();
         Arc::new(Mutex::new(efs))
     }
-
+    /// Open a block device as a filesystem
     pub fn open(block_device: Arc<dyn BlockDevice>) -> Arc<Mutex<Self>> {
         // read SuperBlock
         get_block_cache(0, Arc::clone(&block_device))
@@ -99,7 +103,7 @@ impl EasyFileSystem {
                 Arc::new(Mutex::new(efs))
             })
     }
-
+    /// Get the root inode of the filesystem
     pub fn root_inode(efs: &Arc<Mutex<Self>>) -> Inode {
         let block_device = Arc::clone(&efs.lock().block_device);
         // acquire efs lock temporarily
@@ -107,7 +111,7 @@ impl EasyFileSystem {
         // release efs lock
         Inode::new(block_id, block_offset, Arc::clone(efs), block_device)
     }
-
+    /// Get inode by id
     pub fn get_disk_inode_pos(&self, inode_id: u32) -> (u32, usize) {
         let inode_size = core::mem::size_of::<DiskInode>();
         let inodes_per_block = (BLOCK_SZ / inode_size) as u32;
@@ -117,20 +121,20 @@ impl EasyFileSystem {
             (inode_id % inodes_per_block) as usize * inode_size,
         )
     }
-
+    /// Get data block by id
     pub fn get_data_block_id(&self, data_block_id: u32) -> u32 {
         self.data_area_start_block + data_block_id
     }
-
+    /// Allocate a new inode
     pub fn alloc_inode(&mut self) -> u32 {
         self.inode_bitmap.alloc(&self.block_device).unwrap() as u32
     }
 
-    /// Return a block ID not ID in the data area.
+    /// Allocate a data block
     pub fn alloc_data(&mut self) -> u32 {
         self.data_bitmap.alloc(&self.block_device).unwrap() as u32 + self.data_area_start_block
     }
-
+    /// Deallocate a data block
     pub fn dealloc_data(&mut self, block_id: u32) {
         get_block_cache(block_id as usize, Arc::clone(&self.block_device))
             .lock()