use std::path::PathBuf; use std::sync::Arc; use std::time::Duration; use arc_swap::ArcSwapOption; use futures::future::*; use futures::select; use futures::stream::*; use serde::{Deserialize, Serialize}; use tokio::fs; use tokio::prelude::*; use tokio::sync::{watch, Mutex, Notify}; use garage_util::data; use garage_util::data::*; use garage_util::error::Error; use garage_rpc::membership::System; use garage_rpc::rpc_client::*; use garage_rpc::rpc_server::*; use garage_table::table_sharded::TableShardedReplication; use garage_table::TableReplication; use crate::block_ref_table::*; use crate::garage::Garage; pub const INLINE_THRESHOLD: usize = 3072; const BLOCK_RW_TIMEOUT: Duration = Duration::from_secs(42); const NEED_BLOCK_QUERY_TIMEOUT: Duration = Duration::from_secs(5); const RESYNC_RETRY_TIMEOUT: Duration = Duration::from_secs(10); #[derive(Debug, Serialize, Deserialize)] pub enum Message { Ok, GetBlock(Hash), PutBlock(PutBlockMessage), NeedBlockQuery(Hash), NeedBlockReply(bool), } #[derive(Debug, Serialize, Deserialize)] pub struct PutBlockMessage { pub hash: Hash, #[serde(with = "serde_bytes")] pub data: Vec, } impl RpcMessage for Message {} pub struct BlockManager { pub replication: TableShardedReplication, pub data_dir: PathBuf, pub data_dir_lock: Mutex<()>, pub rc: sled::Tree, pub resync_queue: sled::Tree, pub resync_notify: Notify, pub system: Arc, rpc_client: Arc>, pub garage: ArcSwapOption, } impl BlockManager { pub fn new( db: &sled::Db, data_dir: PathBuf, replication: TableShardedReplication, system: Arc, rpc_server: &mut RpcServer, ) -> Arc { let rc = db .open_tree("block_local_rc") .expect("Unable to open block_local_rc tree"); rc.set_merge_operator(rc_merge); let resync_queue = db .open_tree("block_local_resync_queue") .expect("Unable to open block_local_resync_queue tree"); let rpc_path = "block_manager"; let rpc_client = system.rpc_client::(rpc_path); let block_manager = Arc::new(Self { replication, data_dir, data_dir_lock: Mutex::new(()), rc, resync_queue, resync_notify: Notify::new(), system, rpc_client, garage: ArcSwapOption::from(None), }); block_manager .clone() .register_handler(rpc_server, rpc_path.into()); block_manager } fn register_handler(self: Arc, rpc_server: &mut RpcServer, path: String) { let self2 = self.clone(); rpc_server.add_handler::(path, move |msg, _addr| { let self2 = self2.clone(); async move { self2.handle(&msg).await } }); let self2 = self.clone(); self.rpc_client .set_local_handler(self.system.id, move |msg| { let self2 = self2.clone(); async move { self2.handle(&msg).await } }); } async fn handle(self: Arc, msg: &Message) -> Result { match msg { Message::PutBlock(m) => self.write_block(&m.hash, &m.data).await, Message::GetBlock(h) => self.read_block(h).await, Message::NeedBlockQuery(h) => self.need_block(h).await.map(Message::NeedBlockReply), _ => Err(Error::BadRPC(format!("Unexpected RPC message"))), } } pub async fn spawn_background_worker(self: Arc) { // Launch 2 simultaneous workers for background resync loop preprocessing for i in 0..2usize { let bm2 = self.clone(); let background = self.system.background.clone(); tokio::spawn(async move { tokio::time::delay_for(Duration::from_secs(10)).await; background .spawn_worker(format!("block resync worker {}", i), move |must_exit| { bm2.resync_loop(must_exit) }) .await; }); } } pub async fn write_block(&self, hash: &Hash, data: &[u8]) -> Result { let _lock = self.data_dir_lock.lock().await; let mut path = self.block_dir(hash); fs::create_dir_all(&path).await?; path.push(hex::encode(hash)); if fs::metadata(&path).await.is_ok() { return Ok(Message::Ok); } let mut f = fs::File::create(path).await?; f.write_all(data).await?; drop(f); Ok(Message::Ok) } pub async fn read_block(&self, hash: &Hash) -> Result { let path = self.block_path(hash); let mut f = match fs::File::open(&path).await { Ok(f) => f, Err(e) => { // Not found but maybe we should have had it ?? self.put_to_resync(hash, 0)?; return Err(Into::into(e)); } }; let mut data = vec![]; f.read_to_end(&mut data).await?; drop(f); if data::sha256sum(&data[..]) != *hash { let _lock = self.data_dir_lock.lock().await; warn!("Block {:?} is corrupted. Deleting and resyncing.", hash); fs::remove_file(path).await?; self.put_to_resync(&hash, 0)?; return Err(Error::CorruptData(*hash)); } Ok(Message::PutBlock(PutBlockMessage { hash: *hash, data })) } pub async fn need_block(&self, hash: &Hash) -> Result { let needed = self .rc .get(hash.as_ref())? .map(|x| u64_from_bytes(x.as_ref()) > 0) .unwrap_or(false); if needed { let path = self.block_path(hash); let exists = fs::metadata(&path).await.is_ok(); Ok(!exists) } else { Ok(false) } } fn block_dir(&self, hash: &Hash) -> PathBuf { let mut path = self.data_dir.clone(); path.push(hex::encode(&hash.as_slice()[0..1])); path.push(hex::encode(&hash.as_slice()[1..2])); path } fn block_path(&self, hash: &Hash) -> PathBuf { let mut path = self.block_dir(hash); path.push(hex::encode(hash.as_ref())); path } pub fn block_incref(&self, hash: &Hash) -> Result<(), Error> { let old_rc = self.rc.get(&hash)?; self.rc.merge(&hash, vec![1])?; if old_rc.map(|x| u64_from_bytes(&x[..]) == 0).unwrap_or(true) { self.put_to_resync(&hash, BLOCK_RW_TIMEOUT.as_millis() as u64)?; } Ok(()) } pub fn block_decref(&self, hash: &Hash) -> Result<(), Error> { let new_rc = self.rc.merge(&hash, vec![0])?; if new_rc.map(|x| u64_from_bytes(&x[..]) == 0).unwrap_or(true) { self.put_to_resync(&hash, 0)?; } Ok(()) } fn put_to_resync(&self, hash: &Hash, delay_millis: u64) -> Result<(), Error> { let when = now_msec() + delay_millis; trace!("Put resync_queue: {} {:?}", when, hash); let mut key = u64::to_be_bytes(when).to_vec(); key.extend(hash.as_ref()); self.resync_queue.insert(key, hash.as_ref())?; self.resync_notify.notify(); Ok(()) } async fn resync_loop( self: Arc, mut must_exit: watch::Receiver, ) -> Result<(), Error> { let mut n_failures = 0usize; while !*must_exit.borrow() { if let Some((time_bytes, hash_bytes)) = self.resync_queue.pop_min()? { let time_msec = u64_from_bytes(&time_bytes[0..8]); let now = now_msec(); if now >= time_msec { let mut hash = [0u8; 32]; hash.copy_from_slice(hash_bytes.as_ref()); let hash = Hash::from(hash); if let Err(e) = self.resync_iter(&hash).await { warn!("Failed to resync block {:?}, retrying later: {}", hash, e); self.put_to_resync(&hash, RESYNC_RETRY_TIMEOUT.as_millis() as u64)?; n_failures += 1; if n_failures >= 10 { warn!("Too many resync failures, throttling."); tokio::time::delay_for(Duration::from_secs(1)).await; } } else { n_failures = 0; } } else { self.resync_queue.insert(time_bytes, hash_bytes)?; let delay = tokio::time::delay_for(Duration::from_millis(time_msec - now)); select! { _ = delay.fuse() => (), _ = self.resync_notify.notified().fuse() => (), _ = must_exit.recv().fuse() => (), } } } else { select! { _ = self.resync_notify.notified().fuse() => (), _ = must_exit.recv().fuse() => (), } } } Ok(()) } async fn resync_iter(&self, hash: &Hash) -> Result<(), Error> { let path = self.block_path(hash); let exists = fs::metadata(&path).await.is_ok(); let needed = self .rc .get(hash.as_ref())? .map(|x| u64_from_bytes(x.as_ref()) > 0) .unwrap_or(false); if exists != needed { info!( "Resync block {:?}: exists {}, needed {}", hash, exists, needed ); } if exists && !needed { trace!("Offloading block {:?}", hash); let ring = self.system.ring.borrow().clone(); let mut who = self.replication.replication_nodes(&hash, &ring); who.retain(|id| *id != self.system.id); let msg = Arc::new(Message::NeedBlockQuery(*hash)); let who_needs_fut = who.iter().map(|to| { self.rpc_client .call_arc(*to, msg.clone(), NEED_BLOCK_QUERY_TIMEOUT) }); let who_needs_resps = join_all(who_needs_fut).await; let mut need_nodes = vec![]; for (node, needed) in who.iter().zip(who_needs_resps.into_iter()) { match needed? { Message::NeedBlockReply(needed) => { if needed { need_nodes.push(*node); } } _ => { return Err(Error::Message(format!( "Unexpected response to NeedBlockQuery RPC" ))); } } } if need_nodes.len() > 0 { trace!( "Block {:?} needed by {} nodes, sending", hash, need_nodes.len() ); let put_block_message = Arc::new(self.read_block(hash).await?); let put_resps = join_all(need_nodes.iter().map(|to| { self.rpc_client .call_arc(*to, put_block_message.clone(), BLOCK_RW_TIMEOUT) })) .await; for resp in put_resps { resp?; } } trace!( "Deleting block {:?}, offload finished ({} / {})", hash, need_nodes.len(), who.len() ); fs::remove_file(path).await?; self.resync_queue.remove(&hash)?; } if needed && !exists { // TODO find a way to not do this if they are sending it to us // Let's suppose this isn't an issue for now with the BLOCK_RW_TIMEOUT delay // between the RC being incremented and this part being called. let block_data = self.rpc_get_block(&hash).await?; self.write_block(hash, &block_data[..]).await?; } Ok(()) } pub async fn rpc_get_block(&self, hash: &Hash) -> Result, Error> { let who = self.replication.read_nodes(&hash, &self.system); let resps = self .rpc_client .try_call_many( &who[..], Message::GetBlock(*hash), RequestStrategy::with_quorum(1) .with_timeout(BLOCK_RW_TIMEOUT) .interrupt_after_quorum(true), ) .await?; for resp in resps { if let Message::PutBlock(msg) = resp { return Ok(msg.data); } } Err(Error::Message(format!( "Unable to read block {:?}: no valid blocks returned", hash ))) } pub async fn rpc_put_block(&self, hash: Hash, data: Vec) -> Result<(), Error> { let who = self.replication.write_nodes(&hash, &self.system); self.rpc_client .try_call_many( &who[..], Message::PutBlock(PutBlockMessage { hash, data }), RequestStrategy::with_quorum(self.replication.write_quorum(&self.system)) .with_timeout(BLOCK_RW_TIMEOUT), ) .await?; Ok(()) } pub async fn repair_data_store(&self, must_exit: &watch::Receiver) -> Result<(), Error> { // 1. Repair blocks from RC table let garage = self.garage.load_full().unwrap(); let mut last_hash = None; let mut i = 0usize; for entry in garage.block_ref_table.store.iter() { let (_k, v_bytes) = entry?; let block_ref = rmp_serde::decode::from_read_ref::<_, BlockRef>(v_bytes.as_ref())?; if Some(&block_ref.block) == last_hash.as_ref() { continue; } if !block_ref.deleted.get() { last_hash = Some(block_ref.block); self.put_to_resync(&block_ref.block, 0)?; } i += 1; if i & 0xFF == 0 && *must_exit.borrow() { return Ok(()); } } // 2. Repair blocks actually on disk self.repair_aux_read_dir_rec(&self.data_dir, must_exit) .await?; Ok(()) } fn repair_aux_read_dir_rec<'a>( &'a self, path: &'a PathBuf, must_exit: &'a watch::Receiver, ) -> BoxFuture<'a, Result<(), Error>> { // Lists all blocks on disk and adds them to the resync queue. // This allows us to find blocks we are storing but don't actually need, // so that we can offload them if necessary and then delete them locally. async move { let mut ls_data_dir = fs::read_dir(path).await?; while let Some(data_dir_ent) = ls_data_dir.next().await { let data_dir_ent = data_dir_ent?; let name = data_dir_ent.file_name(); let name = match name.into_string() { Ok(x) => x, Err(_) => continue, }; let ent_type = data_dir_ent.file_type().await?; if name.len() == 2 && hex::decode(&name).is_ok() && ent_type.is_dir() { self.repair_aux_read_dir_rec(&data_dir_ent.path(), must_exit) .await?; } else if name.len() == 64 { let hash_bytes = match hex::decode(&name) { Ok(h) => h, Err(_) => continue, }; let mut hash = [0u8; 32]; hash.copy_from_slice(&hash_bytes[..]); self.put_to_resync(&hash.into(), 0)?; } if *must_exit.borrow() { break; } } Ok(()) } .boxed() } } fn u64_from_bytes(bytes: &[u8]) -> u64 { assert!(bytes.len() == 8); let mut x8 = [0u8; 8]; x8.copy_from_slice(bytes); u64::from_be_bytes(x8) } fn rc_merge(_key: &[u8], old: Option<&[u8]>, new: &[u8]) -> Option> { let old = old.map(u64_from_bytes).unwrap_or(0); assert!(new.len() == 1); let new = match new[0] { 0 => { if old > 0 { old - 1 } else { 0 } } 1 => old + 1, _ => unreachable!(), }; if new == 0 { None } else { Some(u64::to_be_bytes(new).to_vec()) } }