diff --git a/src/lib.rs b/src/lib.rs
index 529b14c..0dbdfab 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -15,12 +15,13 @@ extern crate quickcheck;
 #[cfg(test)]
 extern crate quickcheck_macros;
 
-pub mod io_engine;
 pub mod cache;
 pub mod checksum;
 pub mod file_utils;
+pub mod io_engine;
 pub mod pack;
 pub mod pdata;
+pub mod report;
 pub mod shrink;
 pub mod thin;
 pub mod version;
diff --git a/src/report.rs b/src/report.rs
new file mode 100644
index 0000000..94a76da
--- /dev/null
+++ b/src/report.rs
@@ -0,0 +1,198 @@
+use anyhow::Result;
+use indicatif::{ProgressBar, ProgressStyle};
+use std::sync::Mutex;
+
+//------------------------------------------
+
+#[derive(Clone)]
+pub enum ReportOutcome {
+    Success,
+    NonFatal,
+    Fatal,
+}
+
+use ReportOutcome::*;
+
+impl ReportOutcome {
+    pub fn combine(lhs: &ReportOutcome, rhs: &ReportOutcome) -> ReportOutcome {
+        match (lhs, rhs) {
+            (Success, rhs) => rhs.clone(),
+            (lhs, Success) => lhs.clone(),
+            (Fatal, _) => Fatal,
+            (_, Fatal) => Fatal,
+            (_, _) => NonFatal,
+        }
+    }
+}
+
+pub struct Report {
+    outcome: Mutex<ReportOutcome>,
+    inner: Mutex<Box<dyn ReportInner + Send>>,
+}
+
+trait ReportInner {
+    fn set_title(&mut self, txt: &str) -> Result<()>;
+    fn progress(&mut self, percent: u8) -> Result<()>;
+    fn log(&mut self, txt: &str) -> Result<()>;
+    fn complete(&mut self) -> Result<()>;
+}
+
+impl Report {
+    fn new(inner: Box<dyn ReportInner + Send>) -> Report {
+        Report {
+            outcome: Mutex::new(Success),
+            inner: Mutex::new(inner),
+        }
+    }
+
+    fn update_outcome(&self, rhs: ReportOutcome) {
+        let mut lhs = self.outcome.lock().unwrap();
+        *lhs = ReportOutcome::combine(&lhs, &rhs);
+    }
+
+    pub fn set_title(&self, txt: &str) -> Result<()> {
+        let mut inner = self.inner.lock().unwrap();
+        inner.set_title(txt)
+    }
+
+    pub fn progress(&self, percent: u8) -> Result<()> {
+        let mut inner = self.inner.lock().unwrap();
+        inner.progress(percent)
+    }
+
+    pub fn info(&self, txt: &str) -> Result<()> {
+        let mut inner = self.inner.lock().unwrap();
+        inner.log(txt)
+    }
+
+    pub fn non_fatal(&self, txt: &str) -> Result<()> {
+        self.update_outcome(NonFatal);
+        let mut inner = self.inner.lock().unwrap();
+        inner.log(txt)
+    }
+
+    pub fn fatal(&self, txt: &str) -> Result<()> {
+        self.update_outcome(Fatal);
+        let mut inner = self.inner.lock().unwrap();
+        inner.log(txt)
+    }
+
+    pub fn complete(&mut self) -> Result<()> {
+        let mut inner = self.inner.lock().unwrap();
+        inner.complete()?;
+        Ok(())
+    }
+}
+
+//------------------------------------------
+
+struct PBInner {
+    bar: ProgressBar,
+}
+
+impl ReportInner for PBInner {
+    fn set_title(&mut self, txt: &str) -> Result<()> {
+        let mut fmt = "Checking thin metadata [{bar:40}] Remaining {eta}, ".to_string();
+        fmt.push_str(&txt);
+        self.bar.set_style(
+            ProgressStyle::default_bar()
+                .template(&fmt)
+                .progress_chars("=> "),
+        );
+        Ok(())
+    }
+
+    fn progress(&mut self, percent: u8) -> Result<()> {
+        self.bar.set_position(percent as u64);
+        self.bar.tick();
+        Ok(())
+    }
+
+    fn log(&mut self, txt: &str) -> Result<()> {
+        self.bar.println(txt);
+        Ok(())
+    }
+
+    fn complete(&mut self) -> Result<()> {
+        self.bar.finish();
+        Ok(())
+    }
+}
+
+pub fn mk_progress_bar_report() -> Report {
+    Report::new(Box::new(PBInner {
+        bar: ProgressBar::new(100),
+    }))
+}
+
+//------------------------------------------
+
+struct SimpleInner {
+    last_progress: std::time::SystemTime,
+}
+
+impl SimpleInner {
+    fn new() -> SimpleInner {
+        SimpleInner {
+            last_progress: std::time::SystemTime::now(),
+        }
+    }
+}
+
+impl ReportInner for SimpleInner {
+    fn set_title(&mut self, txt: &str) -> Result<()> {
+        println!("{}", txt);
+        Ok(())
+    }
+
+    fn progress(&mut self, percent: u8) -> Result<()> {
+        let elapsed = self.last_progress.elapsed().unwrap();
+        if elapsed > std::time::Duration::from_secs(5) {
+            println!("Progress: {}%", percent);
+            self.last_progress = std::time::SystemTime::now();
+        }
+        Ok(())
+    }
+
+    fn log(&mut self, txt: &str) -> Result<()> {
+        eprintln!("{}", txt);
+        Ok(())
+    }
+
+    fn complete(&mut self) -> Result<()> {
+        Ok(())
+    }
+}
+
+pub fn mk_simple_report() -> Report {
+    Report::new(Box::new(SimpleInner::new()))
+}
+
+//------------------------------------------
+
+struct QuietInner {
+}
+
+impl ReportInner for QuietInner {
+    fn set_title(&mut self, _txt: &str) -> Result<()> {
+        Ok(())
+    }
+
+    fn progress(&mut self, _percent: u8) -> Result<()> {
+        Ok(())
+    }
+
+    fn log(&mut self, _txt: &str) -> Result<()> {
+        Ok(())
+    }
+
+    fn complete(&mut self) -> Result<()> {
+        Ok(())
+    }
+}
+
+pub fn mk_quiet_report() -> Report {
+    Report::new(Box::new(QuietInner {}))
+}
+
+//------------------------------------------
diff --git a/src/thin/check.rs b/src/thin/check.rs
index 017c4e4..b24f666 100644
--- a/src/thin/check.rs
+++ b/src/thin/check.rs
@@ -1,11 +1,8 @@
 use anyhow::{anyhow, Result};
-use indicatif::{ProgressBar, ProgressStyle};
 use nom::{number::complete::*, IResult};
-use std::collections::BTreeMap;
 use std::path::Path;
-use std::sync::mpsc::{channel, Receiver, Sender, TryRecvError};
 use std::sync::{Arc, Mutex};
-use std::{thread, time};
+use std::thread;
 use threadpool::ThreadPool;
 
 use crate::checksum;
@@ -13,6 +10,7 @@ use crate::io_engine::{AsyncIoEngine, Block, IoEngine, SyncIoEngine};
 use crate::pdata::btree::{btree_to_map, btree_to_map_with_sm, BTreeWalker, Node, NodeVisitor};
 use crate::pdata::space_map::*;
 use crate::pdata::unpack::*;
+use crate::report::*;
 use crate::thin::superblock::*;
 
 //------------------------------------------
@@ -156,143 +154,10 @@ impl<'a> NodeVisitor<u32> for OverflowChecker<'a> {
 
 //------------------------------------------
 
-struct ReportOptions {}
-
-#[derive(Clone)]
-enum ReportOutcome {
-    Success,
-    NonFatal,
-    Fatal,
-}
-
-use ReportOutcome::*;
-
-impl ReportOutcome {
-    fn combine(lhs: &ReportOutcome, rhs: &ReportOutcome) -> ReportOutcome {
-        match (lhs, rhs) {
-            (Success, rhs) => rhs.clone(),
-            (lhs, Success) => lhs.clone(),
-            (Fatal, _) => Fatal,
-            (_, Fatal) => Fatal,
-            (_, _) => NonFatal,
-        }
-    }
-}
-
-enum ReportCmd {
-    Log(String),
-    Complete,
-    Title(String),
-}
-
-struct Report {
-    opts: ReportOptions,
-    outcome: ReportOutcome,
-    tx: Sender<ReportCmd>,
-    tid: thread::JoinHandle<()>,
-}
-
-impl Report {
-    fn new(
-        opts: ReportOptions,
-        sm: Arc<Mutex<dyn SpaceMap + Send + Sync>>,
-        total_allocated: u64,
-    ) -> Result<Report> {
-        let (tx, rx) = channel();
-        let tid = thread::spawn(move || report_thread(sm, total_allocated, rx));
-        Ok(Report {
-            opts,
-            outcome: ReportOutcome::Success,
-            tx,
-            tid,
-        })
-    }
-
-    fn info<I: Into<String>>(&mut self, txt: I) -> Result<()> {
-        self.tx.send(ReportCmd::Log(txt.into()))?;
-        Ok(())
-    }
-
-    fn add_outcome(&mut self, rhs: ReportOutcome) {
-        self.outcome = ReportOutcome::combine(&self.outcome, &rhs);
-    }
-
-    fn non_fatal<I: Into<String>>(&mut self, txt: I) -> Result<()> {
-        self.add_outcome(NonFatal);
-        self.tx.send(ReportCmd::Log(txt.into()))?;
-        Ok(())
-    }
-
-    fn fatal<I: Into<String>>(&mut self, txt: I) -> Result<()> {
-        self.add_outcome(Fatal);
-        self.tx.send(ReportCmd::Log(txt.into()))?;
-        Ok(())
-    }
-
-    fn complete(self) -> Result<()> {
-        self.tx.send(ReportCmd::Complete)?;
-        self.tid.join();
-        Ok(())
-    }
-
-    fn set_title(&mut self, txt: &str) -> Result<()> {
-        self.tx.send(ReportCmd::Title(txt.to_string()))?;
-        Ok(())
-    }
-}
-
-fn report_thread(
-    sm: Arc<Mutex<dyn SpaceMap + Send + Sync>>,
-    total_allocated: u64,
-    rx: Receiver<ReportCmd>,
-) {
-    let interval = time::Duration::from_millis(250);
-    let bar = ProgressBar::new(total_allocated);
-    loop {
-        loop {
-            match rx.try_recv() {
-                Ok(ReportCmd::Log(txt)) => {
-                    bar.println(txt);
-                }
-                Ok(ReportCmd::Complete) => {
-                    bar.finish();
-                    return;
-                }
-                Ok(ReportCmd::Title(txt)) => {
-                    let mut fmt = "Checking thin metadata [{bar:40}] Remaining {eta}, ".to_string();
-                    fmt.push_str(&txt);
-                    bar.set_style(
-                        ProgressStyle::default_bar()
-                            .template(&fmt)
-                            .progress_chars("=> "),
-                    );
-                }
-                Err(TryRecvError::Disconnected) => {
-                    return;
-                }
-                Err(TryRecvError::Empty) => {
-                    break;
-                }
-            }
-        }
-
-        let sm = sm.lock().unwrap();
-        let nr_allocated = sm.get_nr_allocated().unwrap();
-        drop(sm);
-
-        bar.set_position(nr_allocated);
-        bar.tick();
-
-        thread::sleep(interval);
-    }
-}
-
-//------------------------------------------
-
 fn check_space_map(
     kind: &str,
     engine: Arc<dyn IoEngine + Send + Sync>,
-    bar: &mut Report,
+    report: &Arc<Report>,
     entries: Vec<IndexEntry>,
     metadata_sm: Option<Arc<Mutex<dyn SpaceMap + Send + Sync>>>,
     sm: Arc<Mutex<dyn SpaceMap + Send + Sync>>,
@@ -344,7 +209,7 @@ fn check_space_map(
                     if actual == 1 && expected == 0 {
                         leaks += 1;
                     } else if actual != expected as u8 {
-                        bar.fatal(format!("Bad reference count for {} block {}.  Expected {}, but space map contains {}.",
+                        report.fatal(&format!("Bad reference count for {} block {}.  Expected {}, but space map contains {}.",
                                   kind, blocknr, expected, actual))?;
                         fail = true;
                     }
@@ -352,7 +217,7 @@ fn check_space_map(
                 BitmapEntry::Overflow => {
                     let expected = sm.get(blocknr)?;
                     if expected < 3 {
-                        bar.fatal(format!("Bad reference count for {} block {}.  Expected {}, but space map says it's >= 3.",
+                        report.fatal(&format!("Bad reference count for {} block {}.  Expected {}, but space map says it's >= 3.",
                                           kind, blocknr, expected))?;
                         fail = true;
                     }
@@ -363,7 +228,7 @@ fn check_space_map(
     }
 
     if leaks > 0 {
-        bar.non_fatal(format!(
+        report.non_fatal(&format!(
             "{} {} blocks have leaked.  Use --auto-repair to fix.",
             leaks, kind
         ))?;
@@ -421,8 +286,39 @@ pub fn check(opts: &ThinCheckOptions) -> Result<()> {
     let devs = btree_to_map::<DeviceDetail>(engine.clone(), false, sb.details_root)?;
     let nr_devs = devs.len();
     let metadata_sm = core_sm(engine.get_nr_blocks(), nr_devs as u32);
-    let opts = ReportOptions {};
-    let mut report = Report::new(opts, metadata_sm.clone(), nr_allocated_metadata)?;
+    //let report = Arc::new(mk_progress_bar_report());
+    //let report = Arc::new(mk_simple_report());
+    let report = Arc::new(mk_quiet_report());
+
+    let tid;
+    let stop_progress = Arc::new(Mutex::new(false));
+
+    {
+        let report = report.clone();
+        let sm = metadata_sm.clone();
+        let stop_progress = stop_progress.clone();
+        tid = thread::spawn(move || {
+            let interval = std::time::Duration::from_millis(250);
+            loop {
+                {
+                    let stop_progress = stop_progress.lock().unwrap();
+                    if *stop_progress {
+                        break;
+                    }
+                }
+
+                let sm = sm.lock().unwrap();
+
+                let mut n = sm.get_nr_allocated().unwrap();
+                drop(sm);
+                n *= 100;
+                n /= nr_allocated_metadata;
+
+                let _r = report.progress(n as u8);
+                thread::sleep(interval);
+            }
+        });
+    }
 
     report.set_title("device details tree")?;
     let _devs = btree_to_map_with_sm::<DeviceDetail>(
@@ -439,7 +335,8 @@ pub fn check(opts: &ThinCheckOptions) -> Result<()> {
     }
 
     // mapping top level
-    let roots = btree_to_map_with_sm::<u64>(engine.clone(), metadata_sm.clone(), false, sb.mapping_root)?;
+    let roots =
+        btree_to_map_with_sm::<u64>(engine.clone(), metadata_sm.clone(), false, sb.mapping_root)?;
 
     // Check the mappings filling in the data_sm as we go.
     report.set_title("mapping tree")?;
@@ -489,7 +386,7 @@ pub fn check(opts: &ThinCheckOptions) -> Result<()> {
     check_space_map(
         "data",
         engine.clone(),
-        &mut report,
+        &report,
         entries,
         Some(metadata_sm.clone()),
         data_sm.clone(),
@@ -524,14 +421,20 @@ pub fn check(opts: &ThinCheckOptions) -> Result<()> {
     check_space_map(
         "metadata",
         engine.clone(),
-        &mut report,
+        &report,
         entries,
         None,
         metadata_sm.clone(),
         root,
     )?;
 
-    report.complete()?;
+    // Completing consumes the report.
+    {
+        let mut stop_progress = stop_progress.lock().unwrap();
+        *stop_progress = true;
+    }
+
+    tid.join();
     Ok(())
 }