diff --git a/src/block/manager.rs b/src/block/manager.rs
index de9b08c2..fbca74e2 100644
--- a/src/block/manager.rs
+++ b/src/block/manager.rs
@@ -56,6 +56,8 @@ const RESYNC_RETRY_DELAY_MAX_BACKOFF_POWER: u64 = 6;
 // to delete the block locally.
 pub(crate) const BLOCK_GC_DELAY: Duration = Duration::from_secs(600);
 
+type OptKVPair = Option<(Vec<u8>, Vec<u8>)>;
+
 /// RPC messages used to share blocks of data between nodes
 #[derive(Debug, Serialize, Deserialize)]
 pub enum BlockRpc {
@@ -640,7 +642,7 @@ impl BlockManager {
 		}
 	}
 
-	fn resync_get_next(&self) -> Result<Option<(Vec<u8>, Vec<u8>)>, db::Error> {
+	fn resync_get_next(&self) -> Result<OptKVPair, db::Error> {
 		match self.resync_queue.iter()?.next() {
 			None => Ok(None),
 			Some(v) => {
@@ -970,7 +972,7 @@ impl ErrorCounter {
 		}
 	}
 
-	fn decode<'a>(data: db::Value<'a>) -> Self {
+	fn decode(data: db::Value<'_>) -> Self {
 		Self {
 			errors: u64::from_be_bytes(data[0..8].try_into().unwrap()),
 			last_try: u64::from_be_bytes(data[8..16].try_into().unwrap()),
diff --git a/src/db/lib.rs b/src/db/lib.rs
index 4cda121f..95d2c16b 100644
--- a/src/db/lib.rs
+++ b/src/db/lib.rs
@@ -29,14 +29,14 @@ pub type Exporter<'a> = Box<dyn std::iter::Iterator<Item = Result<(String, Value
 
 pub struct Value<'a>(pub(crate) Box<dyn IValue<'a> + 'a>);
 
-pub trait IValue<'a>: AsRef<[u8]> {
-	fn into_vec(&mut self) -> Vec<u8>;
+pub trait IValue<'a>: AsRef<[u8]> + core::borrow::Borrow<[u8]> {
+	fn take_maybe(&mut self) -> Vec<u8>;
 }
 
 impl<'a> Value<'a> {
 	#[inline]
 	pub fn into_vec(mut self) -> Vec<u8> {
-		self.0.into_vec()
+		self.0.take_maybe()
 	}
 }
 
@@ -50,7 +50,7 @@ impl<'a> AsRef<[u8]> for Value<'a> {
 impl<'a> std::borrow::Borrow<[u8]> for Value<'a> {
 	#[inline]
 	fn borrow(&self) -> &[u8] {
-		self.0.as_ref().as_ref()
+		self.0.as_ref().borrow()
 	}
 }
 
@@ -82,7 +82,7 @@ impl<'a> std::fmt::Debug for Value<'a> {
 }
 
 impl<'a> IValue<'a> for Vec<u8> {
-	fn into_vec(&mut self) -> Vec<u8> {
+	fn take_maybe(&mut self) -> Vec<u8> {
 		std::mem::take(self)
 	}
 }
@@ -106,7 +106,7 @@ impl<'a> From<&'a [u8]> for Value<'a> {
 }
 
 impl<'a> IValue<'a> for &'a [u8] {
-	fn into_vec(&mut self) -> Vec<u8> {
+	fn take_maybe(&mut self) -> Vec<u8> {
 		self.to_vec()
 	}
 }
@@ -175,21 +175,22 @@ impl Db {
 		}
 	}
 
-	pub fn export<'a>(&'a self) -> Result<Exporter<'a>> {
+	pub fn export(&self) -> Result<Exporter<'_>> {
 		self.0.export()
 	}
 
-	pub fn import<'a>(&self, ex: Exporter<'a>) -> Result<()> {
+	pub fn import(&self, ex: Exporter<'_>) -> Result<()> {
 		self.0.import(ex)
 	}
 }
 
+#[allow(clippy::len_without_is_empty)]
 impl Tree {
 	pub fn db(&self) -> Db {
 		Db(self.0.clone())
 	}
 
-	pub fn get<'a, T: AsRef<[u8]>>(&'a self, key: T) -> Result<Option<Value<'a>>> {
+	pub fn get<T: AsRef<[u8]>>(&self, key: T) -> Result<Option<Value<'_>>> {
 		self.0.get(self.1, key.as_ref())
 	}
 	pub fn len(&self) -> Result<usize> {
@@ -199,18 +200,18 @@ impl Tree {
 	pub fn insert<T: AsRef<[u8]>, U: AsRef<[u8]>>(&self, key: T, value: U) -> Result<()> {
 		self.0.insert(self.1, key.as_ref(), value.as_ref())
 	}
-	pub fn remove<'a, T: AsRef<[u8]>>(&'a self, key: T) -> Result<bool> {
+	pub fn remove<T: AsRef<[u8]>>(&self, key: T) -> Result<bool> {
 		self.0.remove(self.1, key.as_ref())
 	}
 
-	pub fn iter<'a>(&'a self) -> Result<ValueIter<'a>> {
+	pub fn iter(&self) -> Result<ValueIter<'_>> {
 		self.0.iter(self.1)
 	}
-	pub fn iter_rev<'a>(&'a self) -> Result<ValueIter<'a>> {
+	pub fn iter_rev(&self) -> Result<ValueIter<'_>> {
 		self.0.iter_rev(self.1)
 	}
 
-	pub fn range<'a, K, R>(&'a self, range: R) -> Result<ValueIter<'a>>
+	pub fn range<K, R>(&self, range: R) -> Result<ValueIter<'_>>
 	where
 		K: AsRef<[u8]>,
 		R: RangeBounds<K>,
@@ -219,7 +220,7 @@ impl Tree {
 		let eb = range.end_bound();
 		self.0.range(self.1, get_bound(sb), get_bound(eb))
 	}
-	pub fn range_rev<'a, K, R>(&'a self, range: R) -> Result<ValueIter<'a>>
+	pub fn range_rev<K, R>(&self, range: R) -> Result<ValueIter<'_>>
 	where
 		K: AsRef<[u8]>,
 		R: RangeBounds<K>,
@@ -230,6 +231,7 @@ impl Tree {
 	}
 }
 
+#[allow(clippy::len_without_is_empty)]
 impl<'a> Transaction<'a> {
 	pub fn get<T: AsRef<[u8]>>(&self, tree: &Tree, key: T) -> Result<Option<Value<'a>>> {
 		self.0.get(tree.1, key.as_ref())
@@ -278,12 +280,10 @@ impl<'a> Transaction<'a> {
 
 	// ----
 
-	#[must_use]
 	pub fn abort<R, E>(self, e: E) -> TxResult<R, E> {
 		Err(TxError::Abort(e))
 	}
 
-	#[must_use]
 	pub fn commit<R, E>(self, r: R) -> TxResult<R, E> {
 		Ok(r)
 	}
@@ -294,32 +294,32 @@ impl<'a> Transaction<'a> {
 pub(crate) trait IDb: Send + Sync {
 	fn open_tree(&self, name: &str) -> Result<usize>;
 
-	fn get<'a>(&'a self, tree: usize, key: &[u8]) -> Result<Option<Value<'a>>>;
+	fn get(&self, tree: usize, key: &[u8]) -> Result<Option<Value<'_>>>;
 	fn len(&self, tree: usize) -> Result<usize>;
 
 	fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<()>;
 	fn remove(&self, tree: usize, key: &[u8]) -> Result<bool>;
 
-	fn iter<'a>(&'a self, tree: usize) -> Result<ValueIter<'a>>;
-	fn iter_rev<'a>(&'a self, tree: usize) -> Result<ValueIter<'a>>;
+	fn iter(&self, tree: usize) -> Result<ValueIter<'_>>;
+	fn iter_rev(&self, tree: usize) -> Result<ValueIter<'_>>;
 
-	fn range<'a, 'r>(
-		&'a self,
+	fn range<'r>(
+		&self,
 		tree: usize,
 		low: Bound<&'r [u8]>,
 		high: Bound<&'r [u8]>,
-	) -> Result<ValueIter<'a>>;
-	fn range_rev<'a, 'r>(
-		&'a self,
+	) -> Result<ValueIter<'_>>;
+	fn range_rev<'r>(
+		&self,
 		tree: usize,
 		low: Bound<&'r [u8]>,
 		high: Bound<&'r [u8]>,
-	) -> Result<ValueIter<'a>>;
+	) -> Result<ValueIter<'_>>;
 
 	fn transaction(&self, f: &dyn ITxFn) -> TxResult<(), ()>;
 
-	fn export<'a>(&'a self) -> Result<Exporter<'a>>;
-	fn import<'a>(&self, ex: Exporter<'a>) -> Result<()>;
+	fn export(&self) -> Result<Exporter<'_>>;
+	fn import(&self, ex: Exporter<'_>) -> Result<()>;
 }
 
 pub(crate) trait ITx<'a> {
diff --git a/src/db/sled_adapter.rs b/src/db/sled_adapter.rs
index acee305b..7382776f 100644
--- a/src/db/sled_adapter.rs
+++ b/src/db/sled_adapter.rs
@@ -27,7 +27,7 @@ impl From<sled::Error> for Error {
 // -- val
 
 impl<'a> IValue<'a> for sled::IVec {
-	fn into_vec(&mut self) -> Vec<u8> {
+	fn take_maybe(&mut self) -> Vec<u8> {
 		self.to_vec()
 	}
 }
@@ -52,7 +52,7 @@ pub struct SledDb {
 }
 
 impl SledDb {
-	pub fn new(db: sled::Db) -> Db {
+	pub fn init(db: sled::Db) -> Db {
 		let s = Self {
 			db,
 			trees: RwLock::new((Vec::new(), HashMap::new())),
@@ -67,7 +67,7 @@ impl SledDb {
 			.0
 			.get(i)
 			.cloned()
-			.ok_or(Error("invalid tree id".into()))
+			.ok_or_else(|| Error("invalid tree id".into()))
 	}
 }
 
@@ -87,7 +87,7 @@ impl IDb for SledDb {
 
 	// ----
 
-	fn get<'a>(&'a self, tree: usize, key: &[u8]) -> Result<Option<Value<'a>>> {
+	fn get(&self, tree: usize, key: &[u8]) -> Result<Option<Value<'_>>> {
 		let tree = self.get_tree(tree)?;
 		Ok(tree.get(key)?.map(From::from))
 	}
@@ -108,37 +108,37 @@ impl IDb for SledDb {
 		Ok(())
 	}
 
-	fn iter<'a>(&'a self, tree: usize) -> Result<ValueIter<'a>> {
+	fn iter(&self, tree: usize) -> Result<ValueIter<'_>> {
 		let tree = self.get_tree(tree)?;
 		Ok(Box::new(tree.iter().map(|v| {
 			v.map(|(x, y)| (x.into(), y.into())).map_err(Into::into)
 		})))
 	}
 
-	fn iter_rev<'a>(&'a self, tree: usize) -> Result<ValueIter<'a>> {
+	fn iter_rev(&self, tree: usize) -> Result<ValueIter<'_>> {
 		let tree = self.get_tree(tree)?;
 		Ok(Box::new(tree.iter().rev().map(|v| {
 			v.map(|(x, y)| (x.into(), y.into())).map_err(Into::into)
 		})))
 	}
 
-	fn range<'a, 'r>(
-		&'a self,
+	fn range<'r>(
+		&self,
 		tree: usize,
 		low: Bound<&'r [u8]>,
 		high: Bound<&'r [u8]>,
-	) -> Result<ValueIter<'a>> {
+	) -> Result<ValueIter<'_>> {
 		let tree = self.get_tree(tree)?;
 		Ok(Box::new(tree.range::<&'r [u8], _>((low, high)).map(|v| {
 			v.map(|(x, y)| (x.into(), y.into())).map_err(Into::into)
 		})))
 	}
-	fn range_rev<'a, 'r>(
-		&'a self,
+	fn range_rev<'r>(
+		&self,
 		tree: usize,
 		low: Bound<&'r [u8]>,
 		high: Bound<&'r [u8]>,
-	) -> Result<ValueIter<'a>> {
+	) -> Result<ValueIter<'_>> {
 		let tree = self.get_tree(tree)?;
 		Ok(Box::new(tree.range::<&'r [u8], _>((low, high)).rev().map(
 			|v| v.map(|(x, y)| (x.into(), y.into())).map_err(Into::into),
@@ -178,7 +178,7 @@ impl IDb for SledDb {
 
 	// ----
 
-	fn export<'a>(&'a self) -> Result<Exporter<'a>> {
+	fn export(&self) -> Result<Exporter<'_>> {
 		let mut trees = vec![];
 		for name in self.db.tree_names() {
 			let name = std::str::from_utf8(&name)
@@ -188,17 +188,17 @@ impl IDb for SledDb {
 			let tree = self.trees.read().unwrap().0.get(tree).unwrap().clone();
 			trees.push((name, tree));
 		}
-		let trees_exporter: Exporter<'a> = Box::new(trees.into_iter().map(|(name, tree)| {
-			let iter: ValueIter<'a> = Box::new(
+		let trees_exporter: Exporter<'_> = Box::new(trees.into_iter().map(|(name, tree)| {
+			let iter: ValueIter<'_> = Box::new(
 				tree.iter()
 					.map(|v| v.map(|(x, y)| (x.into(), y.into())).map_err(Into::into)),
 			);
-			Ok((name.to_string(), iter))
+			Ok((name, iter))
 		}));
 		Ok(trees_exporter)
 	}
 
-	fn import<'a>(&self, ex: Exporter<'a>) -> Result<()> {
+	fn import(&self, ex: Exporter<'_>) -> Result<()> {
 		for ex_tree in ex {
 			let (name, data) = ex_tree?;
 
@@ -234,9 +234,11 @@ struct SledTx<'a> {
 
 impl<'a> SledTx<'a> {
 	fn get_tree(&self, i: usize) -> Result<&TransactionalTree> {
-		self.trees.get(i).ok_or(Error(
-			"invalid tree id (it might have been openned after the transaction started)".into(),
-		))
+		self.trees.get(i).ok_or_else(|| {
+			Error(
+				"invalid tree id (it might have been openned after the transaction started)".into(),
+			)
+		})
 	}
 
 	fn save_error<R>(&self, v: std::result::Result<R, UnabortableTransactionError>) -> Result<R> {
diff --git a/src/db/sqlite_adapter.rs b/src/db/sqlite_adapter.rs
index 701639dc..31d20553 100644
--- a/src/db/sqlite_adapter.rs
+++ b/src/db/sqlite_adapter.rs
@@ -35,7 +35,7 @@ pub struct SqliteDb {
 }
 
 impl SqliteDb {
-	pub fn new(db: rusqlite::Connection) -> Db {
+	pub fn init(db: rusqlite::Connection) -> Db {
 		let s = Self {
 			db: Mutex::new(db),
 			trees: RwLock::new(Vec::new()),
@@ -49,7 +49,7 @@ impl SqliteDb {
 			.unwrap()
 			.get(i)
 			.cloned()
-			.ok_or(Error("invalid tree id".into()))
+			.ok_or_else(|| Error("invalid tree id".into()))
 	}
 }
 
@@ -77,7 +77,7 @@ impl IDb for SqliteDb {
 
 	// ----
 
-	fn get<'a>(&'a self, tree: usize, key: &[u8]) -> Result<Option<Value<'a>>> {
+	fn get(&self, tree: usize, key: &[u8]) -> Result<Option<Value<'_>>> {
 		let tree = self.get_tree(tree)?;
 		let db = self.db.lock().unwrap();
 		let mut stmt = db.prepare(&format!("SELECT v FROM {} WHERE k = ?1", tree))?;
@@ -102,7 +102,7 @@ impl IDb for SqliteDb {
 		let mut res_iter = stmt.query([])?;
 		match res_iter.next()? {
 			None => Ok(0),
-			Some(v) => Ok(v.get::<_, usize>(0)?.into()),
+			Some(v) => Ok(v.get::<_, usize>(0)?),
 		}
 	}
 
@@ -116,24 +116,24 @@ impl IDb for SqliteDb {
 		Ok(())
 	}
 
-	fn iter<'a>(&'a self, tree: usize) -> Result<ValueIter<'a>> {
+	fn iter(&self, tree: usize) -> Result<ValueIter<'_>> {
 		let tree = self.get_tree(tree)?;
 		let sql = format!("SELECT k, v FROM {} ORDER BY k ASC", tree);
-		DbValueIterator::new(self.db.lock().unwrap(), &sql, [])
+		DbValueIterator::make(self.db.lock().unwrap(), &sql, [])
 	}
 
-	fn iter_rev<'a>(&'a self, tree: usize) -> Result<ValueIter<'a>> {
+	fn iter_rev(&self, tree: usize) -> Result<ValueIter<'_>> {
 		let tree = self.get_tree(tree)?;
 		let sql = format!("SELECT k, v FROM {} ORDER BY k DESC", tree);
-		DbValueIterator::new(self.db.lock().unwrap(), &sql, [])
+		DbValueIterator::make(self.db.lock().unwrap(), &sql, [])
 	}
 
-	fn range<'a, 'r>(
-		&'a self,
+	fn range<'r>(
+		&self,
 		tree: usize,
 		low: Bound<&'r [u8]>,
 		high: Bound<&'r [u8]>,
-	) -> Result<ValueIter<'a>> {
+	) -> Result<ValueIter<'_>> {
 		let tree = self.get_tree(tree)?;
 
 		let (bounds_sql, params) = bounds_sql(low, high);
@@ -143,18 +143,18 @@ impl IDb for SqliteDb {
 			.iter()
 			.map(|x| x as &dyn rusqlite::ToSql)
 			.collect::<Vec<_>>();
-		DbValueIterator::new::<&[&dyn rusqlite::ToSql]>(
+		DbValueIterator::make::<&[&dyn rusqlite::ToSql]>(
 			self.db.lock().unwrap(),
 			&sql,
 			params.as_ref(),
 		)
 	}
-	fn range_rev<'a, 'r>(
-		&'a self,
+	fn range_rev<'r>(
+		&self,
 		tree: usize,
 		low: Bound<&'r [u8]>,
 		high: Bound<&'r [u8]>,
-	) -> Result<ValueIter<'a>> {
+	) -> Result<ValueIter<'_>> {
 		let tree = self.get_tree(tree)?;
 
 		let (bounds_sql, params) = bounds_sql(low, high);
@@ -164,7 +164,7 @@ impl IDb for SqliteDb {
 			.iter()
 			.map(|x| x as &dyn rusqlite::ToSql)
 			.collect::<Vec<_>>();
-		DbValueIterator::new::<&[&dyn rusqlite::ToSql]>(
+		DbValueIterator::make::<&[&dyn rusqlite::ToSql]>(
 			self.db.lock().unwrap(),
 			&sql,
 			params.as_ref(),
@@ -200,11 +200,11 @@ impl IDb for SqliteDb {
 
 	// ----
 
-	fn export<'a>(&'a self) -> Result<Exporter<'a>> {
+	fn export(&self) -> Result<Exporter<'_>> {
 		unimplemented!()
 	}
 
-	fn import<'a>(&self, ex: Exporter<'a>) -> Result<()> {
+	fn import(&self, ex: Exporter<'_>) -> Result<()> {
 		unimplemented!()
 	}
 
@@ -220,9 +220,11 @@ struct SqliteTx<'a> {
 
 impl<'a> SqliteTx<'a> {
 	fn get_tree(&self, i: usize) -> Result<String> {
-		self.trees.get(i).cloned().ok_or(Error(
-			"invalid tree id (it might have been openned after the transaction started)".into(),
-		))
+		self.trees.get(i).cloned().ok_or_else(|| {
+			Error(
+				"invalid tree id (it might have been openned after the transaction started)".into(),
+			)
+		})
 	}
 }
 
@@ -244,7 +246,7 @@ impl<'a> ITx<'a> for SqliteTx<'a> {
 		let mut res_iter = stmt.query([])?;
 		match res_iter.next()? {
 			None => Ok(0),
-			Some(v) => Ok(v.get::<_, usize>(0)?.into()),
+			Some(v) => Ok(v.get::<_, usize>(0)?),
 		}
 	}
 
@@ -299,13 +301,13 @@ struct DbValueIterator<'a> {
 }
 
 impl<'a> DbValueIterator<'a> {
-	fn new<P: rusqlite::Params>(
+	fn make<P: rusqlite::Params>(
 		db: MutexGuard<'a, Connection>,
 		sql: &str,
 		args: P,
 	) -> Result<ValueIter<'a>> {
 		let res = DbValueIterator {
-			db: db,
+			db,
 			stmt: None,
 			iter: None,
 			_pin: PhantomPinned,
@@ -314,7 +316,7 @@ impl<'a> DbValueIterator<'a> {
 
 		unsafe {
 			let db = NonNull::from(&boxed.db);
-			let stmt = db.as_ref().prepare(&sql)?;
+			let stmt = db.as_ref().prepare(sql)?;
 
 			let mut_ref: Pin<&mut DbValueIterator<'a>> = Pin::as_mut(&mut boxed);
 			Pin::get_unchecked_mut(mut_ref).stmt = Some(stmt);
diff --git a/src/db/test.rs b/src/db/test.rs
index 2f5e4c46..75200cf1 100644
--- a/src/db/test.rs
+++ b/src/db/test.rs
@@ -81,13 +81,13 @@ fn test_suite(db: Db) {
 #[test]
 fn test_sled_db() {
 	let path = mktemp::Temp::new_dir().unwrap();
-	let db = SledDb::new(sled::open(path.to_path_buf()).unwrap());
+	let db = SledDb::init(sled::open(path.to_path_buf()).unwrap());
 	test_suite(db);
 	drop(path);
 }
 
 #[test]
 fn test_sqlite_db() {
-	let db = SqliteDb::new(rusqlite::Connection::open_in_memory().unwrap());
+	let db = SqliteDb::init(rusqlite::Connection::open_in_memory().unwrap());
 	test_suite(db);
 }
diff --git a/src/garage/repair.rs b/src/garage/repair.rs
index a096aaa0..5735d6d0 100644
--- a/src/garage/repair.rs
+++ b/src/garage/repair.rs
@@ -16,6 +16,8 @@ pub struct Repair {
 	pub garage: Arc<Garage>,
 }
 
+type OptKVPair = Option<(Vec<u8>, Vec<u8>)>;
+
 impl Repair {
 	pub async fn repair_worker(&self, opt: RepairOpt, must_exit: watch::Receiver<bool>) {
 		if let Err(e) = self.repair_worker_aux(opt, must_exit).await {
@@ -105,7 +107,7 @@ impl Repair {
 		Ok(())
 	}
 
-	fn get_next_version_after(&self, pos: &[u8]) -> Result<Option<(Vec<u8>, Vec<u8>)>, Error> {
+	fn get_next_version_after(&self, pos: &[u8]) -> Result<OptKVPair, Error> {
 		match self
 			.garage
 			.version_table
@@ -161,7 +163,8 @@ impl Repair {
 		Ok(())
 	}
 
-	fn get_next_block_ref_after(&self, pos: &[u8]) -> Result<Option<(Vec<u8>, Vec<u8>)>, Error> {
+	#[allow(clippy::type_complexity)]
+	fn get_next_block_ref_after(&self, pos: &[u8]) -> Result<OptKVPair, Error> {
 		match self
 			.garage
 			.block_ref_table
diff --git a/src/garage/server.rs b/src/garage/server.rs
index 9d148ee7..b102067e 100644
--- a/src/garage/server.rs
+++ b/src/garage/server.rs
@@ -40,7 +40,7 @@ pub async fn run_server(config_file: PathBuf) -> Result<(), Error> {
 		.flush_every_ms(Some(config.sled_flush_every_ms))
 		.open()
 		.expect("Unable to open sled DB");
-	let db = db::sled_adapter::SledDb::new(db);
+	let db = db::sled_adapter::SledDb::init(db);
 
 	info!("Initializing background runner...");
 	let watch_cancel = netapp::util::watch_ctrl_c();
diff --git a/src/table/data.rs b/src/table/data.rs
index dc1fd445..427ce763 100644
--- a/src/table/data.rs
+++ b/src/table/data.rs
@@ -206,12 +206,8 @@ where
 
 			if value_changed || encoding_changed {
 				let new_bytes_hash = blake2sum(&new_bytes[..]);
-				tx.insert(
-					&self.merkle_todo,
-					tree_key.to_vec(),
-					new_bytes_hash.as_slice(),
-				)?;
-				tx.insert(&self.store, tree_key.to_vec(), new_bytes)?;
+				tx.insert(&self.merkle_todo, tree_key, new_bytes_hash.as_slice())?;
+				tx.insert(&self.store, tree_key, new_bytes)?;
 				Ok(Some((old_entry, new_entry, new_bytes_hash)))
 			} else {
 				Ok(None)