[thin_check (rust)] walk devices tree.

src/pdata/btree.rs

@@ -9,10 +9,11 @@ use crate::checksum;
 //------------------------------------------
 
 pub trait ValueType {
-    type Value;
     // The size of the value when on disk.
     fn disk_size() -> u32;
-    fn unpack(data: &[u8]) -> IResult<&[u8], Self::Value>;
+    fn unpack(data: &[u8]) -> IResult<&[u8], Self>
+    where
+        Self: std::marker::Sized;
 }
 
 const NODE_HEADER_SIZE: usize = 32;
@@ -59,7 +60,7 @@ pub enum Node<V: ValueType> {
     Leaf {
         header: NodeHeader,
         keys: Vec<u64>,
-        values: Vec<V::Value>,
+        values: Vec<V>,
     },
 }
 
@@ -85,8 +86,7 @@ pub fn unpack_node<V: ValueType>(
 
     let (i, header) = to_any(unpack_node_header(data))?;
 
-    // FIXME: lift checks to own fn
-    if header.value_size != V::disk_size() {
+    if header.is_leaf && header.value_size != V::disk_size() {
         return node_err(format!(
             "value_size mismatch: expected {}, was {}",
             V::disk_size(),
@@ -94,7 +94,7 @@ pub fn unpack_node<V: ValueType>(
         ));
     }
 
-    let elt_size = V::disk_size() + 8;
+    let elt_size = header.value_size + 8;
     if elt_size as usize * header.max_entries as usize + NODE_HEADER_SIZE > BLOCK_SIZE {
         return node_err(format!("max_entries is too large ({})", header.max_entries));
     }
@@ -152,11 +152,7 @@ pub fn unpack_node<V: ValueType>(
 
 //------------------------------------------
 
-pub struct ValueU64;
-
-impl ValueType for ValueU64 {
-    type Value = u64;
-
+impl ValueType for u64 {
     fn disk_size() -> u32 {
         8
     }
@@ -180,10 +176,10 @@ pub struct BTreeWalker {
 }
 
 impl BTreeWalker {
-    pub fn new(engine: AsyncIoEngine, ignore_non_fatal: bool) -> BTreeWalker {
+    pub fn new(engine: Arc<AsyncIoEngine>, ignore_non_fatal: bool) -> BTreeWalker {
         let nr_blocks = engine.get_nr_blocks() as usize;
         let r: BTreeWalker = BTreeWalker {
-            engine: Arc::new(engine),
+            engine: engine,
             seen: Arc::new(Mutex::new(FixedBitSet::with_capacity(nr_blocks))),
             ignore_non_fatal,
         };
@@ -242,16 +238,22 @@ impl BTreeWalker {
         Ok(())
     }
 
-    pub fn walk<NV, V>(
-        &mut self,
-        visitor: &mut NV,
-        root: &Block,
-    ) -> Result<()>
+    pub fn walk_b<NV, V>(&mut self, visitor: &mut NV, root: &Block) -> Result<()>
     where
         NV: NodeVisitor<V>,
         V: ValueType,
     {
-       self.walk_node(visitor, &root, true)
+        self.walk_node(visitor, &root, true)
+    }
+
+    pub fn walk<NV, V>(&mut self, visitor: &mut NV, root: u64) -> Result<()>
+    where
+        NV: NodeVisitor<V>,
+        V: ValueType,
+    {
+        let mut root = Block::new(root);
+        self.engine.read(&mut root)?;
+        self.walk_node(visitor, &root, true)
     }
 }
 

src/thin/check.rs

@@ -1,12 +1,13 @@
 use anyhow::{anyhow, Result};
 use nom::{number::complete::*, IResult};
+use std::collections::HashMap;
 use std::path::Path;
 use std::sync::{Arc, Mutex};
 use std::time::Instant;
 use threadpool::ThreadPool;
 
 use crate::block_manager::{AsyncIoEngine, Block, IoEngine};
-use crate::pdata::btree::{BTreeWalker, Node, NodeVisitor, ValueType, ValueU64};
+use crate::pdata::btree::{BTreeWalker, Node, NodeVisitor, ValueType};
 use crate::thin::superblock::*;
 
 //------------------------------------------
@@ -17,11 +18,7 @@ struct BlockTime {
     time: u32,
 }
 
-struct ValueBlockTime;
-
-impl ValueType for ValueBlockTime {
-    type Value = BlockTime;
-
+impl ValueType for BlockTime {
     fn disk_size() -> u32 {
         8
     }
@@ -43,8 +40,8 @@ impl ValueType for ValueBlockTime {
 
 struct TopLevelVisitor {}
 
-impl NodeVisitor<ValueU64> for TopLevelVisitor {
-    fn visit(&mut self, w: &BTreeWalker, _b: &Block, node: &Node<ValueU64>) -> Result<()> {
+impl NodeVisitor<u64> for TopLevelVisitor {
+    fn visit(&mut self, w: &BTreeWalker, _b: &Block, node: &Node<u64>) -> Result<()> {
         if let Node::Leaf {
             header: _h,
             keys,
@@ -77,7 +74,7 @@ impl NodeVisitor<ValueU64> for TopLevelVisitor {
                 let mut w = w.clone();
                 pool.execute(move || {
                     let mut v = BottomLevelVisitor {};
-                    let result = w.walk(&mut v, &b).expect("walk failed"); // FIXME: return error
+                    let result = w.walk_b(&mut v, &b).expect("walk failed"); // FIXME: return error
                     eprintln!("checked thin_dev {} -> {:?}", thin_id, result);
                 });
             }
@@ -91,8 +88,67 @@ impl NodeVisitor<ValueU64> for TopLevelVisitor {
 
 struct BottomLevelVisitor {}
 
-impl NodeVisitor<ValueBlockTime> for BottomLevelVisitor {
-    fn visit(&mut self, _w: &BTreeWalker, _b: &Block, _node: &Node<ValueBlockTime>) -> Result<()> {
+impl NodeVisitor<BlockTime> for BottomLevelVisitor {
+    fn visit(&mut self, _w: &BTreeWalker, _b: &Block, _node: &Node<BlockTime>) -> Result<()> {
+        Ok(())
+    }
+}
+
+//------------------------------------------
+
+#[derive(Clone)]
+struct DeviceDetail {
+    mapped_blocks: u64,
+    transaction_id: u64,
+    creation_time: u32,
+    snapshotted_time: u32,
+}
+
+impl ValueType for DeviceDetail {
+    fn disk_size() -> u32 {
+        24
+    }
+
+    fn unpack(i: &[u8]) -> IResult<&[u8], DeviceDetail> {
+        let (i, mapped_blocks) = le_u64(i)?;
+        let (i, transaction_id) = le_u64(i)?;
+        let (i, creation_time) = le_u32(i)?;
+        let (i, snapshotted_time) = le_u32(i)?;
+
+        Ok((
+            i,
+            DeviceDetail {
+                mapped_blocks,
+                transaction_id,
+                creation_time,
+                snapshotted_time,
+            },
+        ))
+    }
+}
+
+struct DeviceVisitor {
+    devs: HashMap<u32, DeviceDetail>,
+}
+
+impl DeviceVisitor {
+    pub fn new() -> DeviceVisitor {
+        DeviceVisitor {
+            devs: HashMap::new(),
+        }
+    }
+}
+
+impl NodeVisitor<DeviceDetail> for DeviceVisitor {
+    fn visit(&mut self, _w: &BTreeWalker, _b: &Block, node: &Node<DeviceDetail>) -> Result<()> {
+        if let Node::Leaf {header: _h, keys, values} = node {
+           for n in 0..keys.len() {
+               let k = keys[n] as u32;
+               let v = values[n].clone();
+               self.devs.insert(k, v.clone());
+           }
+        }
+
         Ok(())
     }
 }
@@ -101,19 +157,25 @@ impl NodeVisitor<ValueBlockTime> for BottomLevelVisitor {
 
 pub fn check(dev: &Path) -> Result<()> {
     //let mut engine = SyncIoEngine::new(dev)?;
-    let mut engine = AsyncIoEngine::new(dev, 256)?;
+    let mut engine = Arc::new(AsyncIoEngine::new(dev, 256)?);
 
     let now = Instant::now();
-    let sb = read_superblock(&mut engine, SUPERBLOCK_LOCATION)?;
+    let sb = read_superblock(engine.as_ref(), SUPERBLOCK_LOCATION)?;
     eprintln!("{:?}", sb);
-
-    let mut root = Block::new(sb.mapping_root);
-    engine.read(&mut root)?;
-
-    let mut visitor = TopLevelVisitor {};
-    let mut w = BTreeWalker::new(engine, false);
-    let _result = w.walk(&mut visitor, &root)?;
-    println!("read mapping tree in {} ms", now.elapsed().as_millis());
+    
+    {
+        let mut visitor = DeviceVisitor::new();
+        let mut w = BTreeWalker::new(engine.clone(), false);
+        w.walk(&mut visitor, sb.details_root)?;
+        println!("found {} devices", visitor.devs.len());
+    }
+    
+    {
+        let mut visitor = TopLevelVisitor {};
+        let mut w = BTreeWalker::new(engine.clone(), false);
+        let _result = w.walk(&mut visitor, sb.mapping_root)?;
+        println!("read mapping tree in {} ms", now.elapsed().as_millis());
+    }
 
     Ok(())
 }

src/thin/superblock.rs

@@ -85,7 +85,7 @@ fn unpack(data: &[u8]) -> IResult<&[u8], Superblock> {
     ))
 }
 
-pub fn read_superblock<E: IoEngine>(engine: &mut E, loc: u64) -> Result<Superblock> {
+pub fn read_superblock<E: IoEngine>(engine: &E, loc: u64) -> Result<Superblock> {
     let mut b = Block::new(loc);
     engine.read(&mut b)?;