Improve handling of RocksDB corruption (#7630)

* kvdb-rocksdb: update rust-rocksdb version

* kvdb-rocksdb: mark corruptions and attempt repair on db open

* kvdb-rocksdb: better corruption detection on open

* kvdb-rocksdb: add corruption_file_name const

* kvdb-rocksdb: rename mark_corruption to check_for_corruption

util/kvdb-rocksdb/src/lib.rs

@@ -32,7 +32,7 @@ use std::cmp;
 use std::collections::HashMap;
 use std::marker::PhantomData;
 use std::path::{PathBuf, Path};
-use std::{mem, fs, io};
+use std::{fs, io, mem, result};
 
 use parking_lot::{Mutex, MutexGuard, RwLock};
 use rocksdb::{
@@ -257,7 +257,25 @@ pub struct Database {
 	flushing_lock: Mutex<bool>,
 }
 
+#[inline]
+fn check_for_corruption<T, P: AsRef<Path>>(path: P, res: result::Result<T, String>) -> result::Result<T, String> {
+	if let Err(ref s) = res {
+		if s.starts_with("Corruption:") {
+			warn!("DB corrupted: {}. Repair will be triggered on next restart", s);
+			let _ = fs::File::create(path.as_ref().join(Database::CORRUPTION_FILE_NAME));
+		}
+	}
+
+	res
+}
+
+fn is_corrupted(s: &str) -> bool {
+	s.starts_with("Corruption:") || s.starts_with("Invalid argument: You have to open all column families")
+}
+
 impl Database {
+	const CORRUPTION_FILE_NAME: &'static str = "CORRUPTED";
+
 	/// Open database with default settings.
 	pub fn open_default(path: &str) -> Result<Database> {
 		Database::open(&DatabaseConfig::default(), path)
@@ -287,6 +305,14 @@ impl Database {
 			block_opts.set_cache(cache);
 		}
 
+		// attempt database repair if it has been previously marked as corrupted
+		let db_corrupted = Path::new(path).join(Database::CORRUPTION_FILE_NAME);
+		if db_corrupted.exists() {
+			warn!("DB has been previously marked as corrupted, attempting repair");
+			DB::repair(&opts, path)?;
+			fs::remove_file(db_corrupted)?;
+		}
+
 		let columns = config.columns.unwrap_or(0) as usize;
 
 		let mut cf_options = Vec::with_capacity(columns);
@@ -306,12 +332,11 @@ impl Database {
 
 		let mut cfs: Vec<Column> = Vec::new();
 		let db = match config.columns {
-			Some(columns) => {
+			Some(_) => {
 				match DB::open_cf(&opts, path, &cfnames, &cf_options) {
 					Ok(db) => {
 						cfs = cfnames.iter().map(|n| db.cf_handle(n)
 							.expect("rocksdb opens a cf_handle for each cfname; qed")).collect();
-						assert!(cfs.len() == columns as usize);
 						Ok(db)
 					}
 					Err(_) => {
@@ -321,7 +346,7 @@ impl Database {
 								cfs = cfnames.iter().enumerate().map(|(i, n)| db.create_cf(n, &cf_options[i])).collect::<::std::result::Result<_, _>>()?;
 								Ok(db)
 							},
-							err @ Err(_) => err,
+							err => err,
 						}
 					}
 				}
@@ -331,14 +356,18 @@ impl Database {
 
 		let db = match db {
 			Ok(db) => db,
-			Err(ref s) if s.starts_with("Corruption:") => {
-				info!("{}", s);
-				info!("Attempting DB repair for {}", path);
+			Err(ref s) if is_corrupted(s) => {
+				warn!("DB corrupted: {}, attempting repair", s);
 				DB::repair(&opts, path)?;
 
 				match cfnames.is_empty() {
 					true => DB::open(&opts, path)?,
-					false => DB::open_cf(&opts, path, &cfnames, &cf_options)?
+					false => {
+						let db = DB::open_cf(&opts, path, &cfnames, &cf_options)?;
+						cfs = cfnames.iter().map(|n| db.cf_handle(n)
+							.expect("rocksdb opens a cf_handle for each cfname; qed")).collect();
+						db
+					},
 				}
 			},
 			Err(s) => { return Err(s.into()); }
@@ -425,7 +454,11 @@ impl Database {
 						}
 					}
 				}
-				db.write_opt(batch, &self.write_opts)?;
+
+				check_for_corruption(
+					&self.path,
+					db.write_opt(batch, &self.write_opts))?;
+
 				for column in self.flushing.write().iter_mut() {
 					column.clear();
 					column.shrink_to_fit();
@@ -471,7 +504,10 @@ impl Database {
 						},
 					}
 				}
-				db.write_opt(batch, &self.write_opts).map_err(Into::into)
+
+				check_for_corruption(
+					&self.path,
+					db.write_opt(batch, &self.write_opts)).map_err(Into::into)
 			},
 			None => Err("Database is closed".into())
 		}