diff --git a/src/process.rs b/src/process.rs
index 29bf910..46c2023 100644
--- a/src/process.rs
+++ b/src/process.rs
@@ -5,7 +5,11 @@ use std::{
     future::Future,
     pin::Pin,
     process::{ExitStatus, Stdio},
-    task::{Context, Poll},
+    sync::{
+        atomic::{AtomicU8, Ordering},
+        Arc, Mutex,
+    },
+    task::{Context, Poll, Wake, Waker},
     time::{Duration, Instant},
 };
 use tokio::{
@@ -72,14 +76,23 @@ struct DropHandle {
     inner: JoinHandle<()>,
 }
 
-pub(crate) struct ProcessRead<I> {
-    inner: I,
+struct ProcessReadState {
+    flags: AtomicU8,
+    parent: Mutex<Option<Waker>>,
+}
+
+struct ProcessReadWaker {
+    state: Arc<ProcessReadState>,
+    flag: u8,
+}
+
+pub(crate) struct ProcessRead {
+    inner: ChildStdout,
     err_recv: RecvFut<'static, std::io::Error>,
-    err_closed: bool,
-    #[allow(dead_code)]
     handle: DropHandle,
-    eof: bool,
-    sleep: Pin<Box<tokio::time::Sleep>>,
+    closed: bool,
+    state: Arc<ProcessReadState>,
+    span: Span,
 }
 
 #[derive(Debug, thiserror::Error)]
@@ -191,21 +204,21 @@ impl Process {
         }
     }
 
-    pub(crate) fn bytes_read(self, input: Bytes) -> ProcessRead<ChildStdout> {
+    pub(crate) fn bytes_read(self, input: Bytes) -> ProcessRead {
         self.spawn_fn(move |mut stdin| {
             let mut input = input;
             async move { stdin.write_all_buf(&mut input).await }
         })
     }
 
-    pub(crate) fn read(self) -> ProcessRead<ChildStdout> {
+    pub(crate) fn read(self) -> ProcessRead {
         self.spawn_fn(|_| async { Ok(()) })
     }
 
     #[allow(unknown_lints)]
     #[allow(clippy::let_with_type_underscore)]
     #[tracing::instrument(level = "trace", skip_all)]
-    fn spawn_fn<F, Fut>(self, f: F) -> ProcessRead<ChildStdout>
+    fn spawn_fn<F, Fut>(self, f: F) -> ProcessRead
     where
         F: FnOnce(ChildStdin) -> Fut + 'static,
         Fut: Future<Output = std::io::Result<()>>,
@@ -223,7 +236,11 @@ impl Process {
         let (tx, rx) = crate::sync::channel::<std::io::Error>(1);
         let rx = rx.into_recv_async();
 
-        let span = tracing::info_span!(parent: None, "Background process task", %command);
+        let background_span =
+            tracing::info_span!(parent: None, "Background process task", %command);
+        background_span.follows_from(Span::current());
+
+        let span = tracing::info_span!(parent: None, "Foreground process task", %command);
         span.follows_from(Span::current());
 
         let handle = crate::sync::spawn(
@@ -250,81 +267,133 @@ impl Process {
                 let _ = tx.send(error);
                 let _ = child.kill().await;
             }
-            .instrument(span),
+            .instrument(background_span),
         );
 
-        let sleep = tokio::time::sleep(timeout);
-
         ProcessRead {
             inner: stdout,
             err_recv: rx,
-            err_closed: false,
             handle: DropHandle { inner: handle },
-            eof: false,
-            sleep: Box::pin(sleep),
+            closed: false,
+            state: ProcessReadState::new_woken(),
+            span,
         }
     }
 }
 
-impl<I> AsyncRead for ProcessRead<I>
-where
-    I: AsyncRead + Unpin,
-{
+impl ProcessReadState {
+    fn new_woken() -> Arc<Self> {
+        Arc::new(Self {
+            flags: AtomicU8::new(0xff),
+            parent: Mutex::new(None),
+        })
+    }
+
+    fn clone_parent(&self) -> Option<Waker> {
+        let guard = self.parent.lock().unwrap();
+        guard.as_ref().map(|w| w.clone())
+    }
+
+    fn into_parts(self) -> (AtomicU8, Option<Waker>) {
+        let ProcessReadState { flags, parent } = self;
+
+        let parent = parent.lock().unwrap().take();
+
+        (flags, parent)
+    }
+}
+
+impl ProcessRead {
+    fn get_waker(&self, flag: u8) -> Option<Waker> {
+        let mask = 0xff ^ flag;
+        let previous = self.state.flags.fetch_and(mask, Ordering::AcqRel);
+        let active = previous & flag;
+
+        if active == flag {
+            Some(
+                Arc::new(ProcessReadWaker {
+                    state: self.state.clone(),
+                    flag,
+                })
+                .into(),
+            )
+        } else {
+            None
+        }
+    }
+
+    fn set_parent_waker(&self, parent: &Waker) {
+        let mut guard = self.state.parent.lock().unwrap();
+        if let Some(waker) = guard.as_mut() {
+            if !waker.will_wake(parent) {
+                *waker = parent.clone();
+            }
+        } else {
+            *guard = Some(parent.clone());
+        }
+    }
+}
+
+const RECV_WAKER: u8 = 0b_0010;
+const HANDLE_WAKER: u8 = 0b_0100;
+
+impl AsyncRead for ProcessRead {
     fn poll_read(
         mut self: Pin<&mut Self>,
         cx: &mut Context<'_>,
         buf: &mut ReadBuf<'_>,
     ) -> Poll<std::io::Result<()>> {
-        if !self.err_closed {
-            if let Poll::Ready(res) = Pin::new(&mut self.err_recv).poll(cx) {
-                self.err_closed = true;
+        self.set_parent_waker(cx.waker());
 
-                if let Ok(err) = res {
-                    return Poll::Ready(Err(err));
-                }
+        let span = self.span.clone();
+        let guard = span.enter();
 
-                if self.eof {
-                    return Poll::Ready(Ok(()));
-                }
-            }
-
-            if let Poll::Ready(()) = self.sleep.as_mut().poll(cx) {
-                self.err_closed = true;
-
-                return Poll::Ready(Err(std::io::ErrorKind::TimedOut.into()));
-            }
-        }
-
-        if !self.eof {
+        let value = loop {
+            // always poll for bytes when poll_read is called
             let before_size = buf.filled().len();
 
-            return match Pin::new(&mut self.inner).poll_read(cx, buf) {
-                Poll::Ready(Ok(())) => {
-                    if buf.filled().len() == before_size {
-                        self.eof = true;
+            if let Poll::Ready(res) = Pin::new(&mut self.inner).poll_read(cx, buf) {
+                if let Err(e) = res {
+                    self.closed = true;
 
-                        if !self.err_closed {
-                            // reached end of stream & haven't received process signal
-                            return Poll::Pending;
-                        }
+                    break Poll::Ready(Err(e));
+                } else if buf.filled().len() == before_size {
+                    self.closed = true;
+
+                    break Poll::Ready(Ok(()));
+                } else {
+                    break Poll::Ready(Ok(()));
+                }
+            } else if let Some(waker) = self.get_waker(RECV_WAKER) {
+                // only poll recv if we've been explicitly woken
+                let mut recv_cx = Context::from_waker(&waker);
+
+                if let Poll::Ready(res) = Pin::new(&mut self.err_recv).poll(&mut recv_cx) {
+                    if let Ok(err) = res {
+                        self.closed = true;
+                        break Poll::Ready(Err(err));
                     }
-
-                    Poll::Ready(Ok(()))
                 }
-                Poll::Ready(Err(e)) => {
-                    self.eof = true;
+            } else if let Some(waker) = self.get_waker(HANDLE_WAKER) {
+                // only poll handle if we've been explicitly woken
+                let mut handle_cx = Context::from_waker(&waker);
 
-                    Poll::Ready(Err(e))
+                if let Poll::Ready(res) = Pin::new(&mut self.handle.inner).poll(&mut handle_cx) {
+                    if let Err(e) = res {
+                        self.closed = true;
+                        break Poll::Ready(Err(std::io::Error::new(std::io::ErrorKind::Other, e)));
+                    }
                 }
-                Poll::Pending => Poll::Pending,
-            };
-        }
+            } else if self.closed {
+                break Poll::Ready(Ok(()));
+            } else {
+                break Poll::Pending;
+            }
+        };
 
-        if self.err_closed && self.eof {
-            return Poll::Ready(Ok(()));
-        }
+        drop(guard);
 
-        Poll::Pending
+        value
     }
 }
 
@@ -334,6 +403,40 @@ impl Drop for DropHandle {
     }
 }
 
+impl Wake for ProcessReadWaker {
+    fn wake(self: Arc<Self>) {
+        match Arc::try_unwrap(self) {
+            Ok(ProcessReadWaker { state, flag }) => match Arc::try_unwrap(state) {
+                Ok(state) => {
+                    let (flags, parent) = state.into_parts();
+
+                    flags.fetch_and(flag, Ordering::AcqRel);
+
+                    if let Some(parent) = parent {
+                        parent.wake();
+                    }
+                }
+                Err(state) => {
+                    state.flags.fetch_or(flag, Ordering::AcqRel);
+
+                    if let Some(waker) = state.clone_parent() {
+                        waker.wake();
+                    }
+                }
+            },
+            Err(this) => this.wake_by_ref(),
+        }
+    }
+
+    fn wake_by_ref(self: &Arc<Self>) {
+        self.state.flags.fetch_or(self.flag, Ordering::AcqRel);
+
+        if let Some(parent) = self.state.clone_parent() {
+            parent.wake();
+        }
+    }
+}
+
 impl std::fmt::Display for StatusError {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         write!(f, "Command failed with bad status: {}", self.0)
diff --git a/src/repo/migrate.rs b/src/repo/migrate.rs
index 4545b27..5f32fba 100644
--- a/src/repo/migrate.rs
+++ b/src/repo/migrate.rs
@@ -1,4 +1,7 @@
-use std::sync::{Arc, OnceLock};
+use std::{
+    sync::{Arc, OnceLock},
+    time::Duration,
+};
 
 use streem::IntoStreamer;
 use tokio::{sync::Semaphore, task::JoinSet};
@@ -6,7 +9,7 @@ use tokio::{sync::Semaphore, task::JoinSet};
 use crate::{
     config::Configuration,
     details::Details,
-    error::Error,
+    error::{Error, UploadError},
     repo::{ArcRepo, DeleteToken, Hash},
     repo_04::{
         AliasRepo as _, HashRepo as _, IdentifierRepo as _, SettingsRepo as _,
@@ -41,7 +44,7 @@ pub(crate) async fn migrate_repo(old_repo: ArcRepo, new_repo: ArcRepo) -> Result
     let mut index = 0;
     while let Some(res) = hash_stream.next().await {
         if let Ok(hash) = res {
-            let _ = migrate_hash(old_repo.clone(), new_repo.clone(), hash).await;
+            migrate_hash(old_repo.clone(), new_repo.clone(), hash).await;
         } else {
             tracing::warn!("Failed to read hash, skipping");
         }
@@ -61,6 +64,12 @@ pub(crate) async fn migrate_repo(old_repo: ArcRepo, new_repo: ArcRepo) -> Result
             .await?;
     }
 
+    if let Some(generator_state) = old_repo.get(crate::NOT_FOUND_KEY).await? {
+        new_repo
+            .set(crate::NOT_FOUND_KEY, generator_state.to_vec().into())
+            .await?;
+    }
+
     tracing::info!("Migration complete");
 
     Ok(())
@@ -181,7 +190,7 @@ async fn migrate_hash_04<S: Store>(
 ) {
     let mut hash_failures = 0;
 
-    while let Err(e) = do_migrate_hash_04(
+    while let Err(e) = timed_migrate_hash_04(
         &tmp_dir,
         &old_repo,
         &new_repo,
@@ -275,6 +284,22 @@ async fn do_migrate_hash(old_repo: &ArcRepo, new_repo: &ArcRepo, hash: Hash) ->
     Ok(())
 }
 
+async fn timed_migrate_hash_04<S: Store>(
+    tmp_dir: &TmpDir,
+    old_repo: &OldSledRepo,
+    new_repo: &ArcRepo,
+    store: &S,
+    config: &Configuration,
+    old_hash: sled::IVec,
+) -> Result<(), Error> {
+    tokio::time::timeout(
+        Duration::from_secs(config.media.external_validation_timeout * 6),
+        do_migrate_hash_04(tmp_dir, old_repo, new_repo, store, config, old_hash),
+    )
+    .await
+    .map_err(|_| UploadError::ProcessTimeout)?
+}
+
 #[tracing::instrument(skip_all)]
 async fn do_migrate_hash_04<S: Store>(
     tmp_dir: &TmpDir,