unauthorized access with LiteDB[BUG] in database in mode share

[AliAbuHilu]

Version
Which LiteDB LiteDB" Version="5.0.10" / Windows 10 /.NET framework 4.5 are you using. (REQUIRED)

Describe the bug
I'm not getting access to the database when the application is not an administrator , database in mode share

Code to Reproduce
private LiteDB.ConnectionString configConnection;
string strConnection = @"c:\RegStatusMonitor\RegStatusMonitor.db";

if (!Directory.Exists(strConnection))
{
	Directory.CreateDirectory(strConnection);
}
configConnection = new ConnectionString
{
	Filename = strConnection,
	Password = strContato,
	Connection = ConnectionType.Shared
};

using (var db = new LiteDatabase(configConnection))
{


	var colEnvio = db.GetCollection<Model.MonitoramentoEnvio>("MonitoramentoEnvio");

	// cria instânica de monitoramento Envio
	Model.MonitoramentoEnvio MonitoramentoEnvio = new Model.MonitoramentoEnvio
	{
	idDispositvo = _config.eqpIdDispositivo,
	campo = codigo_status,
	valor = valor_status,
	data = data_mudanca,
	cavId = iCavid
	};

	ret = colEnvio.Insert(MonitoramentoEnvio);

}	

Expected behavior
record saved successfully when user is not administrator in shared mode

Screenshots/Stacktrace
Failed to Record Record - [10], [System.UnauthorizedAccessException: Access to the path 'Global \ FFBAB3EC7319D08E60E44B4EA5FA83570C27F817.Mutex' was denied. || in System.IO .__ Error.WinIOError (Int32 errorCode, String maybeFullPath) || in System.Threading.Mutex.MutexTryCodeHelper.MutexTryCode (Object userData) || in System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup (TryCode code, CleanupCode backoutCode, Object userData) || in System.Threading.Mutex.CreateMutexWithGuaranteedCleanup (Boolean initiallyOwned, String name, Boolean & createdNew, SECURITY_ATTRIBUTES secAttrs) || in System.Threading.Mutex..ctor (Boolean initiallyOwned, String name, Boolean & createdNew, MutexSecurity mutexSecurity) || in LiteDB.SharedEngine..ctor (EngineSettings settings) || in LiteDB.ConnectionString.CreateEngine () || in LiteDB.LiteDatabase..ctor (ConnectionString connectionString, BsonMapper mapper) || in RegStatusMonitor.Status.gravaPing (Int32 codigo_status, String valor_status)]

Additional context
this is a dll component that will be accessed by several non-administrator users

[escherrer]

I'm also running into this. I'm using LiteDB to log requests in a web.api app. Strangely it only happens in an Azure App Service, and doesn't have this issue when running in IIS. Both are running .Net 4.8. LiteDB is v5.0.10.

First I get UnauthorizedAccessException:

2021-04-23 00:00:11.8705|ERROR|RSSProxy.Controllers.CLSController|System.UnauthorizedAccessException: Access to the path is denied.
at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
at System.IO.__Error.WinIOError()
at System.IO.FileStream.FlushOSBuffer()
at System.IO.FileStream.Flush(Boolean flushToDisk)
at LiteDB.StreamExtensions.FlushToDisk(Stream stream)
at LiteDB.Engine.DiskService.Write(IEnumerable`1 pages, FileOrigin origin)
at LiteDB.Engine.WalIndexService.CheckpointInternal()
at LiteDB.Engine.WalIndexService.TryCheckpoint()
at LiteDB.Engine.LiteEngine.Dispose(Boolean disposing)
at LiteDB.Engine.LiteEngine.Dispose()
at LiteDB.LiteDatabase.Dispose(Boolean disposing)
at LiteDB.LiteDatabase.Dispose()
at RSSProxy.DataAccess.AdDataAccess.SaveProxyRequest(ProxyRequest proxyRequest) in D:\a\1\s\src\RSSProxy\DataAccess\AdDataAccess.cs:line 123
at RSSProxy.Controllers.CLSController.LogProxyRequest(String destination, HttpStatusCode httpStatusCode) in D:\a\1\s\src\RSSProxy\Controllers\CLSController.cs:line 300
at RSSProxy.Controllers.CLSController.Get(String destination) in D:\a\1\s\src\RSSProxy\Controllers\CLSController.cs:line 249

Then I get IOException for every request thereafter:

2021-04-23 00:00:13.7924|ERROR|RSSProxy.Controllers.CLSController|System.IO.IOException: The process cannot access the file 'D:\home\data\Ad.db' because it is being used by another process.
at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost)
at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options)
at LiteDB.Engine.FileStreamFactory.GetStream(Boolean canWrite, Boolean sequencial)
at LiteDB.Engine.StreamPool.<>c__DisplayClass3_0.<.ctor>b__0()
at System.Lazy1.CreateValue() at System.Lazy1.LazyInitValue()
at System.Lazy`1.get_Value()
at LiteDB.Engine.DiskService..ctor(EngineSettings settings, Int32[] memorySegmentSizes)
at LiteDB.Engine.LiteEngine..ctor(EngineSettings settings)
at LiteDB.ConnectionString.CreateEngine()
at LiteDB.LiteDatabase..ctor(ConnectionString connectionString, BsonMapper mapper)
at RSSProxy.DataAccess.AdDataAccess.GetLiteDatabase() in D:\a\1\s\src\RSSProxy\DataAccess\AdDataAccess.cs:line 38
at RSSProxy.DataAccess.AdDataAccess.SaveProxyRequest(ProxyRequest proxyRequest) in D:\a\1\s\src\RSSProxy\DataAccess\AdDataAccess.cs:line 116
at RSSProxy.Controllers.CLSController.LogProxyRequest(String destination, HttpStatusCode httpStatusCode) in D:\a\1\s\src\RSSProxy\Controllers\CLSController.cs:line 300
at RSSProxy.Controllers.CLSController.Get(String destination) in D:\a\1\s\src\RSSProxy\Controllers\CLSController.cs:line 249

Here is the data access class. It is singleton using Ninject:

using System;
using System.Collections.Generic;
using System.Configuration;
using System.IO;
using System.Linq;
using LiteDB;
using NLog;

namespace RSSProxy.DataAccess
{
    public class AdDataAccess : IAdDataAccess
    {
        private readonly string _dbLocation;
        private readonly Logger _logger;
        private readonly object _locker = new object();

        public AdDataAccess()
        {
            _logger = LogManager.GetLogger(typeof(AdDataAccess).FullName);
            _logger.Debug("Ctor - Begin");

            string dbFolder = ConfigurationManager.AppSettings["dbLocation"];
            Directory.CreateDirectory(dbFolder);
            _dbLocation = dbFolder + "Ad.db";

            _logger.Debug("Ctor - End: DB location: " + _dbLocation);
        }

        private ILiteDatabase GetLiteDatabase()
        {
            var connString = new ConnectionString
            {
                Filename = _dbLocation,
                Connection = ConnectionType.Direct
            };

            return new LiteDatabase(connString);
        }

        public Ad GetAd(string id)
        {
            lock (_locker)
            {
                _logger.Debug("GetAd - Begin");

                Ad result;
                using (var db = GetLiteDatabase())
                {
                    var col = db.GetCollection<Ad>();
                    result = col.FindById(id);
                }

                _logger.Debug("GetAd - End");

                return result;
            }
        }

        public void SaveAd(Ad ad)
        {
            lock (_locker)
            {
                _logger.Debug("SaveAd - Begin");

                using (var db = GetLiteDatabase())
                {
                    var col = db.GetCollection<Ad>();

                    col.Upsert(ad);
                }

                _logger.Debug("SaveAd - End");
            }
        }

        public int PurgeAds(int daysOld)
        {
            lock (_locker)
            {
                _logger.Debug("PurgeAds - Begin");

                int deleteCount = 0;
                using (var db = GetLiteDatabase())
                {
                    var col = db.GetCollection<Ad>();

                    var oldAds = new List<Ad>();
                    foreach (Ad ad in col.FindAll())
                    {
                        if ((ad.GetLastUpdate().CaptureDateTime - DateTime.UtcNow).TotalDays > daysOld)
                        {
                            oldAds.Add(ad);
                        }
                    }

                    foreach (var oldAd in oldAds)
                    {
                        deleteCount++;
                        col.Delete(oldAd.Id);
                    }

                    _logger.Debug("Ads deleted: {0}", deleteCount);
                }

                _logger.Debug("PurgeAds - End");

                return deleteCount;
            }
        }

        public void SaveProxyRequest(ProxyRequest proxyRequest)
        {
            lock (_locker)
            {
                _logger.Debug("SaveProxyRequest - Begin");

                using (var db = GetLiteDatabase())
                {
                    var col = db.GetCollection<ProxyRequest>();

                    col.Upsert(proxyRequest);
                }

                _logger.Debug("SaveProxyRequest - End");
            }
        }

        public int PurgeProxyRequests()
        {
            lock (_locker)
            {
                _logger.Debug("PurgeProxyRequests - Begin");

                int deleteCount;
                using (var db = GetLiteDatabase())
                {
                    ILiteCollection<ProxyRequest> col = db.GetCollection<ProxyRequest>();

                    var cutoffDate = DateTime.UtcNow.AddDays(-2);
                    deleteCount = col.DeleteMany(x => x.RequestDateTime < cutoffDate);

                    _logger.Debug(deleteCount + " old requests deleted");
                }

                _logger.Debug("PurgeProxyRequests - End");

                return deleteCount;
            }
        }

        public List<ProxyRequest> GetProxyRequests()
        {
            lock (_locker)
            {
                _logger.Debug("GetProxyRequests - Begin");

                List<ProxyRequest> result;

                using (var db = GetLiteDatabase())
                {
                    ILiteCollection<ProxyRequest> col = db.GetCollection<ProxyRequest>();
                    result = col.FindAll().ToList();
                }

                _logger.Debug("GetProxyRequests - End");

                return result;
            }
        }
    }

[rexcardan]

I just put in a PR with the fix. Can you try it: #1998

[adamdriscoll]

I was also able to work around this in an Azure App Service with my change mentioned here: #1622 (comment)