diff --git a/src/cache/fs.rs b/src/cache/fs.rs
index a81702a..e60de4d 100644
--- a/src/cache/fs.rs
+++ b/src/cache/fs.rs
@@ -9,10 +9,10 @@ use std::time::Duration;
 use bytes::{Bytes, BytesMut};
 use futures::{Future, Stream, StreamExt};
 use once_cell::sync::Lazy;
-use parking_lot::RwLock;
 use reqwest::Error;
 use tokio::fs::{remove_file, File};
 use tokio::io::{AsyncRead, AsyncWriteExt, ReadBuf};
+use tokio::sync::RwLock;
 use tokio::time::Sleep;
 
 /// Keeps track of files that are currently being written to.
@@ -39,6 +39,7 @@ pub async fn read_file(path: &Path) -> Option<Result<FromFsStream, std::io::Erro
     if path.exists() {
         let status = WRITING_STATUS
             .read()
+            .await
             .get(path)
             .map_or_else(|| Arc::new(CacheStatus::done()), Arc::clone);
 
@@ -50,14 +51,14 @@ pub async fn read_file(path: &Path) -> Option<Result<FromFsStream, std::io::Erro
 
 /// Maps the input byte stream into one that writes to disk instead, returning
 /// a stream that reads from disk instead.
-pub async fn transparent_file_stream(
+pub async fn write_file(
     path: &Path,
     mut byte_stream: impl Stream<Item = Result<Bytes, Error>> + Unpin + Send + 'static,
 ) -> Result<FromFsStream, std::io::Error> {
     let done_writing_flag = Arc::new(CacheStatus::new());
 
     let mut file = {
-        let mut write_lock = WRITING_STATUS.write();
+        let mut write_lock = WRITING_STATUS.write().await;
         let file = File::create(path).await?; // we need to make sure the file exists and is truncated.
         write_lock.insert(path.to_path_buf(), Arc::clone(&done_writing_flag));
         file
@@ -87,7 +88,7 @@ pub async fn transparent_file_stream(
             file.sync_all().await?; // we need metadata
         }
 
-        let mut write_lock = WRITING_STATUS.write();
+        let mut write_lock = WRITING_STATUS.write().await;
         // This needs to be written atomically with the write lock, else
         // it's possible we have an inconsistent state
         if errored {
diff --git a/src/cache/low_mem.rs b/src/cache/low_mem.rs
index eb17794..d3ff8a4 100644
--- a/src/cache/low_mem.rs
+++ b/src/cache/low_mem.rs
@@ -37,8 +37,11 @@ impl Cache for LowMemCache {
         }
     }
 
-    async fn put_stream(&mut self, key: CacheKey, image: ByteStream) {
-        // this call has a side effect and the returned future is for reading
-        let _ = super::fs::transparent_file_stream(&PathBuf::from(key), image);
+    async fn put_stream(
+        &mut self,
+        key: CacheKey,
+        image: ByteStream,
+    ) -> Result<FromFsStream, std::io::Error> {
+        super::fs::write_file(&PathBuf::from(key), image).await
     }
 }
diff --git a/src/cache/mod.rs b/src/cache/mod.rs
index 060766f..55819b0 100644
--- a/src/cache/mod.rs
+++ b/src/cache/mod.rs
@@ -147,7 +147,11 @@ pub trait Cache: Send + Sync {
         unimplemented!()
     }
 
-    async fn put_stream(&mut self, _key: CacheKey, _image: ByteStream) {
+    async fn put_stream(
+        &mut self,
+        _key: CacheKey,
+        _image: ByteStream,
+    ) -> Result<FromFsStream, std::io::Error> {
         unimplemented!()
     }
 }
diff --git a/src/config.rs b/src/config.rs
index 9d507c7..6d936e9 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -37,4 +37,6 @@ pub struct CliArgs {
     pub enable_server_string: bool,
     #[clap(short, long, conflicts_with("memory-quota"), env = "LOW_MEMORY_MODE")]
     pub low_memory: bool,
+    #[clap(short, long, parse(from_occurrences))]
+    pub verbose: usize,
 }
diff --git a/src/main.rs b/src/main.rs
index 09a8701..5d20e51 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,6 +1,6 @@
 #![warn(clippy::pedantic, clippy::nursery)]
 // We're end users, so these is ok
-#![allow(clippy::future_not_send, clippy::module_name_repetitions)]
+#![allow(clippy::module_name_repetitions)]
 
 use std::env::{self, VarError};
 use std::process;
@@ -53,7 +53,9 @@ async fn main() -> Result<(), std::io::Error> {
 
     println!(concat!(
         env!("CARGO_PKG_NAME"),
-        "  Copyright (C) 2021  Edward Shen\n\n",
+        "  Copyright (C) 2021  ",
+        env!("CARGO_PKG_AUTHORS"),
+        "\n\n",
         env!("CARGO_PKG_NAME"),
         " is free software: you can redistribute it and/or modify\n\
         it under the terms of the GNU General Public License as published by\n\
@@ -76,10 +78,13 @@ async fn main() -> Result<(), std::io::Error> {
     let cache_path = cli_args.cache_path.clone();
     let low_mem_mode = cli_args.low_memory;
 
-    SimpleLogger::new()
-        .with_level(LevelFilter::Info)
-        .init()
-        .unwrap();
+    match cli_args.verbose {
+        0 => SimpleLogger::new().with_level(LevelFilter::Info),
+        1 => SimpleLogger::new().with_level(LevelFilter::Debug),
+        _ => SimpleLogger::new().with_level(LevelFilter::Trace),
+    }
+    .init()
+    .unwrap();
 
     let client_secret = if let Ok(v) = env::var("CLIENT_SECRET") {
         v