From a5677e804aaa11ef1fa29df310bece44887680de Mon Sep 17 00:00:00 2001
From: Andrew Thornton <art27@cantab.net>
Date: Sat, 26 Feb 2022 19:55:52 +0000
Subject: [PATCH 1/2] Adjust error for already locked db and prevent level db
 lock on malformed connstr

This PR adjusts the error returned when there is failure to lock the level db, and
permits a connections to the same leveldb where there is a different connection string.

Reference #18921
Reference #18917

Signed-off-by: Andrew Thornton <art27@cantab.net>
---
 modules/nosql/manager_leveldb.go | 36 ++++++++++++++++++++++++++++----
 1 file changed, 32 insertions(+), 4 deletions(-)

diff --git a/modules/nosql/manager_leveldb.go b/modules/nosql/manager_leveldb.go
index eeb0cf74d91a4..581553f0d515c 100644
--- a/modules/nosql/manager_leveldb.go
+++ b/modules/nosql/manager_leveldb.go
@@ -5,10 +5,12 @@
 package nosql
 
 import (
+	"fmt"
 	"path"
 	"strconv"
 	"strings"
 
+	"code.gitea.io/gitea/modules/log"
 	"github.com/syndtr/goleveldb/leveldb"
 	"github.com/syndtr/goleveldb/leveldb/errors"
 	"github.com/syndtr/goleveldb/leveldb/opt"
@@ -40,6 +42,12 @@ func (m *Manager) CloseLevelDB(connection string) error {
 
 // GetLevelDB gets a levelDB for a particular connection
 func (m *Manager) GetLevelDB(connection string) (*leveldb.DB, error) {
+	// Convert the provided connection description to the common format
+	uri := ToLevelDBURI(connection)
+
+	// Get the datadir
+	dataDir := path.Join(uri.Host, uri.Path)
+
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 	db, ok := m.LevelDBConnections[connection]
@@ -48,12 +56,28 @@ func (m *Manager) GetLevelDB(connection string) (*leveldb.DB, error) {
 
 		return db.db, nil
 	}
-	uri := ToLevelDBURI(connection)
+
+	db, ok = m.LevelDBConnections[uri.String()]
+	if ok {
+		db.count++
+
+		return db.db, nil
+	}
+
+	// if there is already a connection to this leveldb reuse that
+	// NOTE: if there differing options then only the first leveldb connection will be used
+	db, ok = m.LevelDBConnections[dataDir]
+	if ok {
+		db.count++
+		log.Warn("Duplicate connnection to level db: %s with different connection strings. Initial connection: %s. This connection: %s", dataDir, db.name[0], connection)
+		db.name = append(db.name, connection)
+		m.LevelDBConnections[connection] = db
+		return db.db, nil
+	}
 	db = &levelDBHolder{
-		name: []string{connection, uri.String()},
+		name: []string{connection, uri.String(), dataDir},
 	}
 
-	dataDir := path.Join(uri.Host, uri.Path)
 	opts := &opt.Options{}
 	for k, v := range uri.Query() {
 		switch replacer.Replace(strings.ToLower(k)) {
@@ -134,7 +158,11 @@ func (m *Manager) GetLevelDB(connection string) (*leveldb.DB, error) {
 	db.db, err = leveldb.OpenFile(dataDir, opts)
 	if err != nil {
 		if !errors.IsCorrupted(err) {
-			return nil, err
+			if strings.Contains(err.Error(), "resource temporarily unavailable") {
+				return nil, fmt.Errorf("unable to lock level db at %s: %w", dataDir, err)
+			}
+
+			return nil, fmt.Errorf("unable to open level db at %s: %w", dataDir, err)
 		}
 		db.db, err = leveldb.RecoverFile(dataDir, opts)
 		if err != nil {

From b125ad25aee580b544e78cd8da57a026b2dd9856 Mon Sep 17 00:00:00 2001
From: Andrew Thornton <art27@cantab.net>
Date: Sun, 27 Feb 2022 15:40:24 +0000
Subject: [PATCH 2/2] On close also check datadir

Signed-off-by: Andrew Thornton <art27@cantab.net>
---
 modules/nosql/manager_leveldb.go | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/modules/nosql/manager_leveldb.go b/modules/nosql/manager_leveldb.go
index 581553f0d515c..97f917af78c5c 100644
--- a/modules/nosql/manager_leveldb.go
+++ b/modules/nosql/manager_leveldb.go
@@ -22,8 +22,16 @@ func (m *Manager) CloseLevelDB(connection string) error {
 	defer m.mutex.Unlock()
 	db, ok := m.LevelDBConnections[connection]
 	if !ok {
-		connection = ToLevelDBURI(connection).String()
-		db, ok = m.LevelDBConnections[connection]
+		// Try the full URI
+		uri := ToLevelDBURI(connection)
+		db, ok = m.LevelDBConnections[uri.String()]
+
+		if !ok {
+			// Try the datadir directly
+			dataDir := path.Join(uri.Host, uri.Path)
+
+			db, ok = m.LevelDBConnections[dataDir]
+		}
 	}
 	if !ok {
 		return nil