It fully works!

crates/librqbit/src/session_persistence/json.rs

@@ -181,7 +181,11 @@ impl BitVFactory for JsonSessionPersistenceStore {
     async fn load(&self, id: TorrentIdOrHash) -> anyhow::Result<Option<Box<dyn BitV>>> {
         let h = self.to_hash(id).await?;
         let filename = self.bitv_filename(&h);
-        let f = match std::fs::OpenOptions::new().write(true).open(&filename) {
+        let f = match std::fs::OpenOptions::new()
+            .read(true)
+            .write(true)
+            .open(&filename)
+        {
             Ok(f) => f,
             Err(e) => match e.kind() {
                 std::io::ErrorKind::NotFound => return Ok(None),
@@ -203,18 +207,23 @@ impl BitVFactory for JsonSessionPersistenceStore {
             .write(true)
             .create(true)
             .truncate(true)
-            .open(&filename)
+            .open(&tmp_filename)
             .await
             .with_context(|| format!("error opening {filename:?}"))?;
         tokio::io::copy(&mut b.as_raw_slice(), &mut dst)
             .await
             .context("error writing bitslice to {filename:?}")?;
-        tokio::fs::rename(tmp_filename, &filename).await?;
+        tokio::fs::rename(&tmp_filename, &filename)
+            .await
+            .with_context(|| format!("error renaming {tmp_filename:?} to {filename:?}"))?;
         let f = std::fs::OpenOptions::new()
+            .read(true)
             .write(true)
             .open(&filename)
             .with_context(|| format!("error opening {filename:?}"))?;
-        Ok(MmapBitV::new(f)?.into_dyn())
+        Ok(MmapBitV::new(f)
+            .with_context(|| format!("error constructing MmapBitV from file {filename:?}"))?
+            .into_dyn())
     }
 }
 
@@ -241,11 +250,15 @@ impl SessionPersistenceStore for JsonSessionPersistenceStore {
         if let Some(t) = removed {
             debug!(?id, "deleted from in-memory db, flushing");
             self.flush().await?;
-            let tf = self.torrent_bytes_filename(&t.info_hash);
-            if let Err(e) = tokio::fs::remove_file(&tf).await {
-                warn!(error=?e, filename=?tf, "error removing torrent file");
-            } else {
-                debug!(filename=?tf, "removed");
+            for tf in [
+                self.torrent_bytes_filename(&t.info_hash),
+                self.bitv_filename(&t.info_hash),
+            ] {
+                if let Err(e) = tokio::fs::remove_file(&tf).await {
+                    warn!(error=?e, filename=?tf, "error removing");
+                } else {
+                    debug!(filename=?tf, "removed");
+                }
             }
         } else {
             bail!("error deleting: didn't find torrent id={id}")

crates/librqbit/src/torrent_state/initializing.rs

@@ -99,7 +99,10 @@ impl TorrentStateInitializing {
                     )
                     .initial_check(&self.checked_bytes)
                 })?;
-                bitv_factory.store_initial_check(id, have_pieces).await?
+                bitv_factory
+                    .store_initial_check(id, have_pieces)
+                    .await
+                    .context("error storing initial check bitfield")?
             }
         };