Layer 1 test not passing

4 files changed, 142 insertions, 24 deletions

diff --git a/src/disk/allocation.rs b/src/disk/allocation.rs
index 291a136..3622e4f 100644
--- a/src/disk/allocation.rs
+++ b/src/disk/allocation.rs
@@ -1,15 +1,16 @@
-use crate::memory::cached_block::convert;
-use crate::disk::data_block::{DataBlock, DoubleIndirectBlock, IndirectBlock, TripleIndirectBlock};
+use crate::disk::block::{DataBlock, DoubleIndirectBlock, IndirectBlock, TripleIndirectBlock};
 use crate::disk::inode::Inode;
+use crate::memory::cached_block::convert;
 use crate::AyaFS;
 
 impl AyaFS {
     /// 为 Inode 分配新 block, 返回 block 的编号
-    pub(crate) fn allocate_block(&mut self, inode: &mut Inode) -> Option<u32> {
+    pub(crate) fn allocate_block_for(&mut self, inode: &mut Inode) -> Option<u32> {
         // 先看这个 inode 的 direct block 有没有空闲
         for index in inode.direct.iter_mut() {
             if !self.data_bitmap.query(*index as usize) {
                 let block_index = self.data_bitmap.allocate().unwrap() as u32;
+                println!("allocating {} for direct", block_index);
                 *index = block_index;
                 inode.n_blocks += 1;
                 // 当调用 get_inode_mut 拿出 &mut Inode 的时候对应的 block 在 cache 里已经脏了
@@ -23,9 +24,11 @@ impl AyaFS {
                 .data_bitmap
                 .allocate()
                 .expect("No free space for new block") as u32;
+            println!("allocating {} for indirect", inode.single_indirect);
         }
         // 在 indirect block 里尝试分配
         if let Some(block_index) = self.allocate_in_indirect(inode.single_indirect) {
+            println!("allocating {} in indirect", block_index);
             inode.n_blocks += 1;
             return Some(block_index);
         }
@@ -36,9 +39,11 @@ impl AyaFS {
                 .data_bitmap
                 .allocate()
                 .expect("No free space for new block") as u32;
+            println!("allocating {} for double indirect", inode.double_indirect);
         }
         // 在 double indirect block 里尝试分配
         if let Some(block_index) = self.alloc_in_double_indirect(inode.double_indirect) {
+            println!("allocating {} in double indirect", block_index);
             inode.n_blocks += 1;
             return Some(block_index);
         }
@@ -49,9 +54,11 @@ impl AyaFS {
                 .data_bitmap
                 .allocate()
                 .expect("No free space for new block") as u32;
+            println!("allocating {} for triple indirect", inode.triple_indirect);
         }
         // 在 double indirect block 里尝试分配
         if let Some(block_index) = self.alloc_in_triple_indirect(inode.triple_indirect) {
+            println!("allocating {} in triple indirect", block_index);
             inode.n_blocks += 1;
             return Some(block_index);
         }
@@ -61,11 +68,13 @@ impl AyaFS {
     fn allocate_in_indirect(&mut self, indirect_entry: u32) -> Option<u32> {
         // 取出 single indirect block, 尝试在里面分配
         let indirect_entry = indirect_entry as usize;
+        // println!("finding indirect block with number {}, bitmap says {}", indirect_entry, self.data_bitmap.query(indirect_entry));
 
         if let Some(block) = self
             .get_block(indirect_entry)
             .map(convert::<DataBlock, IndirectBlock>)
         {
+            // println!("found indirect block with number {}", indirect_entry);
             let mut indirect_block = block.clone();
             for entry in indirect_block.block.entries.iter_mut() {
                 if self.data_bitmap.query(*entry as usize) == false {
@@ -130,3 +139,119 @@ impl AyaFS {
         None
     }
 }
+
+impl AyaFS {
+    /// 从 inode 中删去最后一个 block
+    pub(crate) fn deallocate_block(&mut self, inode: &mut Inode) -> Option<u32> {
+        // 如果 triple indirect 块存在, 则尝试从中销毁一个块
+        if self.data_bitmap.query(inode.triple_indirect as usize) {
+            if let Some(block_index) = self.deallocate_from_triple_indirect(inode.triple_indirect) {
+                inode.n_blocks -= 1;
+                return Some(block_index); // 销毁成功, 直接返回
+            } else {
+                // 销毁失败, 说明 triple indirect 空了, 把它也销毁.
+                self.data_bitmap.deallocate(inode.triple_indirect as usize);
+                inode.triple_indirect = 0; // 这个地方理论上应该不用?
+            }
+        }
+        // 如果 double indirect 块存在, 则从其中销毁
+        if self.data_bitmap.query(inode.double_indirect as usize) {
+            if let Some(block_index) = self.deallocate_from_double_indirect(inode.double_indirect) {
+                inode.n_blocks -= 1;
+                return Some(block_index);
+            } else {
+                self.data_bitmap.deallocate(inode.double_indirect as usize);
+                inode.double_indirect = 0; // 这个地方理论上应该不用?
+            }
+        }
+        // 如果 indirect 块存在, 则从其中销毁
+        if self.data_bitmap.query(inode.single_indirect as usize) {
+            if let Some(block_index) = self.deallocate_from_indirect(inode.single_indirect) {
+                inode.n_blocks -= 1;
+                return Some(block_index);
+            } else {
+                self.data_bitmap.deallocate(inode.single_indirect as usize);
+                inode.single_indirect = 0; // 这个地方理论上应该不用?
+            }
+        }
+        // 都没有，直接从 direct 块中销毁
+        for entry in inode.direct.iter_mut().rev() {
+            if self.data_bitmap.query(*entry as usize) {
+                let index = std::mem::replace(entry, 0); // let index = *entry; *entry = 0;
+                inode.n_blocks -= 1;
+                self.data_bitmap.deallocate(index as usize);
+                return Some(index);
+            }
+        }
+        None
+    }
+
+    fn deallocate_from_triple_indirect(&mut self, triple_indirect_entry: u32) -> Option<u32> {
+        let triple_indirect_entry = triple_indirect_entry as usize;
+        if let Some(triple_indirect_block) = self
+            .peek_block(triple_indirect_entry)
+            .map(convert::<DataBlock, TripleIndirectBlock>)
+        {
+            for double_indirect_entry in triple_indirect_block
+                .block
+                .double_indirect
+                .into_iter()
+                .rev()
+            {
+                // 如果这个位置的 double indirect 存在
+                if self.data_bitmap.query(double_indirect_entry as usize) {
+                    // 尝试从中销毁一个块
+                    if let Some(block_index) =
+                        self.deallocate_from_double_indirect(double_indirect_entry)
+                    {
+                        return Some(block_index); // 成功则直接返回
+                    } else {
+                        // 失败则把这个 double indirect 销毁
+                        self.data_bitmap.deallocate(double_indirect_entry as usize);
+                    }
+                }
+            }
+        }
+        None
+    }
+
+    fn deallocate_from_double_indirect(&mut self, double_indirect_entry: u32) -> Option<u32> {
+        let double_indirect_entry = double_indirect_entry as usize;
+        if let Some(double_indirect_block) = self
+            .peek_block(double_indirect_entry)
+            .map(convert::<DataBlock, DoubleIndirectBlock>)
+        {
+            for indirect_entry in double_indirect_block.block.indirect.into_iter().rev() {
+                // 如果这个位置的 indirect 存在
+                if self.data_bitmap.query(indirect_entry as usize) {
+                    // 尝试从中销毁一个块
+                    if let Some(block_index) = self.deallocate_from_indirect(indirect_entry) {
+                        return Some(block_index); // 成功则直接返回
+                    } else {
+                        // 失败则把这个 indirect 销毁
+                        self.data_bitmap.deallocate(indirect_entry as usize);
+                    }
+                }
+            }
+        }
+        None
+    }
+
+    fn deallocate_from_indirect(&mut self, indirect_entry: u32) -> Option<u32> {
+        let indirect_entry = indirect_entry as usize;
+        if let Some(indirect_block) = self
+            .peek_block(indirect_entry)
+            .map(convert::<DataBlock, IndirectBlock>)
+        {
+            // 遍历 indirect block 里的每个 block
+            for entry in indirect_block.block.entries.into_iter().rev() {
+                // 如果这个 block 存在, 销毁它
+                if self.data_bitmap.query(entry as usize) {
+                    self.data_bitmap.deallocate(entry as usize);
+                    return Some(entry);
+                }
+            }
+        }
+        None
+    }
+}
diff --git a/src/disk/bitmap.rs b/src/disk/bitmap.rs
index 64389c2..b68c341 100644
--- a/src/disk/bitmap.rs
+++ b/src/disk/bitmap.rs
@@ -1,5 +1,4 @@
 use crate::block_device::{BlockDevice, BLOCK_SIZE};
-use std::cell::RefCell;
 use std::sync::Arc;
 
 pub struct Bitmap {
@@ -10,7 +9,7 @@ pub struct Bitmap {
 }
 
 impl Bitmap {
-    pub fn new(starting_block: usize, length: usize, device: Arc<dyn BlockDevice>) -> Self {
+    pub(crate) fn new(starting_block: usize, length: usize, device: Arc<dyn BlockDevice>) -> Self {
         Self {
             starting_block,
             length,
@@ -18,8 +17,7 @@ impl Bitmap {
             data: vec![0u8; length * BLOCK_SIZE],
         }
     }
-    pub fn allocate(&mut self) -> Option<usize> {
-        // let mut data = self.data.borrow_mut();
+    pub(crate) fn allocate(&mut self) -> Option<usize> {
         for (i, byte) in self.data.iter_mut().enumerate() {
             let leading_ones = byte.leading_ones();
             if leading_ones != 8 {
@@ -28,11 +26,9 @@ impl Bitmap {
             }
         }
         None
-        // panic!("No more space for allocation!")
     }
 
-    pub fn query(&self, index: usize) -> bool {
-        // let data = self.data.borrow();
+    pub(crate) fn query(&self, index: usize) -> bool {
         if index == 0 {
             false
         } else {
@@ -40,15 +36,13 @@ impl Bitmap {
         }
     }
 
-    // fn write_back(&mut self) {
-    //     for block_index_offset in self.dirty_blocks.iter() {
-    //         let buffer_front_index = BLOCK_SIZE * block_index_offset;
-    //         let buffer_back_index = BLOCK_SIZE * (block_index_offset + 1);
-    //         self.device.write(
-    //             self.starting_block + block_index_offset,
-    //             &self.data[buffer_front_index..buffer_back_index],
-    //         );
-    //     }
-    //     self.dirty_blocks = Vec::new();
-    // }
+    pub(crate) fn deallocate(&mut self, index: usize) -> bool {
+        if self.query(index) {
+            let mask = !(1u8 << (7 - index % 8));
+            self.data[index / 8] &= mask;
+            true
+        } else {
+            false
+        }
+    }
 }
diff --git a/src/disk/data_block.rs b/src/disk/block.rs
index d287ee6..d287ee6 100644
--- a/src/disk/data_block.rs
+++ b/src/disk/block.rs
diff --git a/src/disk/mod.rs b/src/disk/mod.rs
index 65f313c..878e832 100644
--- a/src/disk/mod.rs
+++ b/src/disk/mod.rs
@@ -1,7 +1,6 @@
+pub mod allocation;
 /// On-disk data structures and logic.
 /// Including bitmaps, inodes and blocks.
-
 pub mod bitmap;
+pub mod block;
 pub mod inode;
-pub mod data_block;
-pub mod allocation;