From f0df17af9e06e3754c67441ceebd4a24f76c6bd7 Mon Sep 17 00:00:00 2001
From: Joe Thornber <ejt@redhat.com>
Date: Mon, 10 Aug 2020 08:59:02 +0100
Subject: [PATCH] [thin_check (rust)] Get SyncIoEngine working again.

---
 src/io_engine.rs       | 24 +++++++++++++-----------
 src/pdata/btree.rs     |  6 +++---
 src/thin/check.rs      |  5 +++--
 src/thin/superblock.rs |  2 +-
 4 files changed, 20 insertions(+), 17 deletions(-)

diff --git a/src/io_engine.rs b/src/io_engine.rs
index fe68bb7..5b0a313 100644
--- a/src/io_engine.rs
+++ b/src/io_engine.rs
@@ -4,7 +4,7 @@ use io_uring::IoUring;
 use std::alloc::{alloc, dealloc, Layout};
 use std::fs::File;
 use std::fs::OpenOptions;
-use std::io;
+use std::io::{self, Seek, Read};
 use std::os::unix::fs::OpenOptionsExt;
 use std::os::unix::io::{AsRawFd, RawFd};
 use std::path::Path;
@@ -60,10 +60,9 @@ fn get_nr_blocks(path: &Path) -> io::Result<u64> {
 
 //------------------------------------------
 
-/*
 pub struct SyncIoEngine {
     nr_blocks: u64,
-    input: File,
+    input: Mutex<File>,
 }
 
 impl SyncIoEngine {
@@ -76,7 +75,7 @@ impl SyncIoEngine {
 
         Ok(SyncIoEngine {
             nr_blocks: get_nr_blocks(path)?,
-            input,
+            input: Mutex::new(input),
         })
     }
 }
@@ -86,23 +85,26 @@ impl IoEngine for SyncIoEngine {
         self.nr_blocks
     }
 
-    fn read(&mut self, b: &mut Block) -> Result<()> {
-        self.input
-            .seek(io::SeekFrom::Start(b.loc * BLOCK_SIZE as u64))?;
-        self.input.read_exact(&mut b.get_data())?;
+
+    fn read(&self, b: &mut Block) -> Result<()> {
+        let mut input = self.input.lock().unwrap();
+        input.seek(io::SeekFrom::Start(b.loc * BLOCK_SIZE as u64))?;
+        input.read_exact(&mut b.get_data())?;
 
         Ok(())
     }
 
-    fn read_many(&mut self, blocks: &mut Vec<Block>) -> Result<()> {
+    fn read_many(&self, blocks: &mut Vec<Block>) -> Result<()> {
+        let mut input = self.input.lock().unwrap();
         for b in blocks {
-            self.read(b);
+            input.seek(io::SeekFrom::Start(b.loc * BLOCK_SIZE as u64))?;
+            input.read_exact(&mut b.get_data())?;
         }
 
         Ok(())
     }
 }
-*/
+
 //------------------------------------------
 
 pub struct AsyncIoEngine_ {
diff --git a/src/pdata/btree.rs b/src/pdata/btree.rs
index 9a61aff..50bf8f8 100644
--- a/src/pdata/btree.rs
+++ b/src/pdata/btree.rs
@@ -189,13 +189,13 @@ pub trait NodeVisitor<V: Unpack> {
 
 #[derive(Clone)]
 pub struct BTreeWalker {
-    pub engine: Arc<AsyncIoEngine>,
+    pub engine: Arc<dyn IoEngine + Send + Sync>,
     pub seen: Arc<Mutex<FixedBitSet>>,
     ignore_non_fatal: bool,
 }
 
 impl BTreeWalker {
-    pub fn new(engine: Arc<AsyncIoEngine>, ignore_non_fatal: bool) -> BTreeWalker {
+    pub fn new(engine: Arc<dyn IoEngine + Send + Sync>, ignore_non_fatal: bool) -> BTreeWalker {
         let nr_blocks = engine.get_nr_blocks() as usize;
         let r: BTreeWalker = BTreeWalker {
             engine,
@@ -206,7 +206,7 @@ impl BTreeWalker {
     }
 
     pub fn new_with_seen(
-        engine: Arc<AsyncIoEngine>,
+        engine: Arc<dyn IoEngine + Send + Sync>,
         seen: Arc<Mutex<FixedBitSet>>,
         ignore_non_fatal: bool,
     ) -> BTreeWalker {
diff --git a/src/thin/check.rs b/src/thin/check.rs
index 3ef76c5..a93eaaf 100644
--- a/src/thin/check.rs
+++ b/src/thin/check.rs
@@ -7,7 +7,7 @@ use std::sync::{Arc, Mutex};
 use std::time::Instant;
 use threadpool::ThreadPool;
 
-use crate::io_engine::{AsyncIoEngine, Block, IoEngine};
+use crate::io_engine::{AsyncIoEngine, SyncIoEngine, Block, IoEngine};
 use crate::checksum;
 use crate::pdata::btree::{unpack, BTreeWalker, Node, NodeVisitor, Unpack};
 use crate::pdata::space_map::*;
@@ -265,7 +265,8 @@ impl<'a> NodeVisitor<u32> for OverflowChecker<'a> {
 const MAX_CONCURRENT_IO: u32 = 1024;
 
 pub fn check(dev: &Path) -> Result<()> {
-    let engine = Arc::new(AsyncIoEngine::new(dev, MAX_CONCURRENT_IO)?);
+    //let engine = Arc::new(AsyncIoEngine::new(dev, MAX_CONCURRENT_IO)?);
+    let engine: Arc<dyn IoEngine + Send + Sync> = Arc::new(SyncIoEngine::new(dev)?);
 
     let now = Instant::now();
     let sb = read_superblock(engine.as_ref(), SUPERBLOCK_LOCATION)?;
diff --git a/src/thin/superblock.rs b/src/thin/superblock.rs
index bd3e8ba..3bb2637 100644
--- a/src/thin/superblock.rs
+++ b/src/thin/superblock.rs
@@ -85,7 +85,7 @@ fn unpack(data: &[u8]) -> IResult<&[u8], Superblock> {
     ))
 }
 
-pub fn read_superblock<E: IoEngine>(engine: &E, loc: u64) -> Result<Superblock> {
+pub fn read_superblock(engine: &dyn IoEngine, loc: u64) -> Result<Superblock> {
     let mut b = Block::new(loc);
     engine.read(&mut b)?;