From 9112897efb4d6d224a58910e1d48e4571b5e0460 Mon Sep 17 00:00:00 2001
From: Martin Marmsoler <martin.marmsoler@gmail.com>
Date: Tue, 28 May 2024 08:11:14 +0200
Subject: [PATCH] WIP

---
 src/fat/fat_table.rs | 21 ++++++++++-----------
 src/volume_mgr.rs    |  2 +-
 2 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/src/fat/fat_table.rs b/src/fat/fat_table.rs
index b141d3f..ffbb394 100644
--- a/src/fat/fat_table.rs
+++ b/src/fat/fat_table.rs
@@ -1,25 +1,23 @@
 /// FAT table definition
 /// 
 /// 
-use crate::{
-    blockdevice::BlockCount,
-    fat::FatType,
-};
+use crate::fat::FatType;
 use byteorder::{ByteOrder, LittleEndian};
 
+/// Represents a single FAT table. It contains all information about which cluster is occupied
+/// from a file
 pub struct FatTable<'a> {
     fat_type: FatType,
-    data: &'a mut [u8; 512],
+    data: &'a mut [u8],
 }
 
 impl<'a> FatTable<'a> {
-
-    pub fn create_from_bytes(data: &mut [u8; 512], fat_type: FatType) -> Result<Self, &'static str> {
-        let mut table = Self {
+    /// Attempt to parse a FAT table from a multiple sectors.
+    pub fn create_from_bytes(data: &'a mut [u8], fat_type: FatType) -> Result<Self, &'static str> {
+        Ok(Self {
             data,
             fat_type,
-        };
-        Ok(table)
+        })
     }
 
     // FAT16 only
@@ -30,6 +28,7 @@ impl<'a> FatTable<'a> {
 
     const FAT16_DIRTY_BIT: u16 = 15;
     const FAT32_DIRTY_BIT: u32 = 27;
+
     pub (crate) fn dirty(&self) -> bool {
         match self.fat_type {
             FatType::Fat16 => (LittleEndian::read_u16(&self.data[2..2+2]) & (1 << Self::FAT16_DIRTY_BIT)) == 0,
@@ -37,7 +36,7 @@ impl<'a> FatTable<'a> {
         }
     }
 
-    pub (crate) fn set_dirty(&self, dirty: bool) {
+    pub (crate) fn set_dirty(&mut self, dirty: bool) {
         match self.fat_type {
             FatType::Fat16 => {
                 let mut v = LittleEndian::read_u16(&self.data[2..2+2]);
diff --git a/src/volume_mgr.rs b/src/volume_mgr.rs
index a1fedc6..e121de7 100644
--- a/src/volume_mgr.rs
+++ b/src/volume_mgr.rs
@@ -714,7 +714,7 @@ where
                 let mut blocks = [Block::new()];
                 self.block_device.read(&mut blocks, f.lba_start + f.fat_start, "reading fat table");
                 let mut block = &mut blocks[0];
-                let fat_table = fat::FatTable::create_from_bytes(&mut block.contents, f.get_fat_type()).map_err(Error::FormatError)?;
+                let mut fat_table = fat::FatTable::create_from_bytes(&mut block.contents, f.get_fat_type()).map_err(Error::FormatError)?;
                 fat_table.set_dirty(true);
                 if f.fat_nums == 1 || f.fat_nums == 2 {
                     self.block_device.write(&blocks, f.lba_start + f.fat_start).await?;