Add comments in ch6

easy-fs/src/vfs.rs

@@ -6,7 +6,7 @@ use alloc::string::String;
 use alloc::sync::Arc;
 use alloc::vec::Vec;
 use spin::{Mutex, MutexGuard};
-
+/// Virtual filesystem layer over easy-fs
 pub struct Inode {
     block_id: usize,
     block_offset: usize,
@@ -15,7 +15,7 @@ pub struct Inode {
 }
 
 impl Inode {
-    /// We should not acquire efs lock here.
+    /// Create a vfs inode
     pub fn new(
         block_id: u32,
         block_offset: usize,
@@ -29,19 +29,19 @@ impl Inode {
             block_device,
         }
     }
-
+    /// Call a function over a disk inode to read it
     fn read_disk_inode<V>(&self, f: impl FnOnce(&DiskInode) -> V) -> V {
         get_block_cache(self.block_id, Arc::clone(&self.block_device))
             .lock()
             .read(self.block_offset, f)
     }
-
+    /// Call a function over a disk inode to modify it
     fn modify_disk_inode<V>(&self, f: impl FnOnce(&mut DiskInode) -> V) -> V {
         get_block_cache(self.block_id, Arc::clone(&self.block_device))
             .lock()
             .modify(self.block_offset, f)
     }
-
+    /// Find inode under a disk inode by name
     fn find_inode_id(&self, name: &str, disk_inode: &DiskInode) -> Option<u32> {
         // assert it is a directory
         assert!(disk_inode.is_dir());
@@ -58,7 +58,7 @@ impl Inode {
         }
         None
     }
-
+    /// Find inode under current inode by name
     pub fn find(&self, name: &str) -> Option<Arc<Inode>> {
         let fs = self.fs.lock();
         self.read_disk_inode(|disk_inode| {
@@ -73,7 +73,7 @@ impl Inode {
             })
         })
     }
-
+    /// Increase the size of a disk inode
     fn increase_size(
         &self,
         new_size: u32,
@@ -90,7 +90,7 @@ impl Inode {
         }
         disk_inode.increase_size(new_size, v, &self.block_device);
     }
-
+    /// Create inode under current inode by name
     pub fn create(&self, name: &str) -> Option<Arc<Inode>> {
         let mut fs = self.fs.lock();
         let op = |root_inode: &DiskInode| {
@@ -138,7 +138,7 @@ impl Inode {
         )))
         // release efs lock automatically by compiler
     }
-
+    /// List inodes under current inode
     pub fn ls(&self) -> Vec<String> {
         let _fs = self.fs.lock();
         self.read_disk_inode(|disk_inode| {
@@ -155,12 +155,12 @@ impl Inode {
             v
         })
     }
-
+    /// Read data from current inode
     pub fn read_at(&self, offset: usize, buf: &mut [u8]) -> usize {
         let _fs = self.fs.lock();
         self.read_disk_inode(|disk_inode| disk_inode.read_at(offset, buf, &self.block_device))
     }
-
+    /// Write data to current inode
     pub fn write_at(&self, offset: usize, buf: &[u8]) -> usize {
         let mut fs = self.fs.lock();
         let size = self.modify_disk_inode(|disk_inode| {
@@ -170,7 +170,7 @@ impl Inode {
         block_cache_sync_all();
         size
     }
-
+    /// Clear the data in current inode
     pub fn clear(&self) {
         let mut fs = self.fs.lock();
         self.modify_disk_inode(|disk_inode| {