1 files changed, 45 insertions, 11 deletions
diff --git a/Jellyfin.Server.Implementations/FullSystemBackup/BackupService.cs b/Jellyfin.Server.Implementations/FullSystemBackup/BackupService.cs
index a6dc5458ee..7c10a5dc77 100644
--- a/Jellyfin.Server.Implementations/FullSystemBackup/BackupService.cs
+++ b/Jellyfin.Server.Implementations/FullSystemBackup/BackupService.cs
@@ -12,6 +12,7 @@ using Jellyfin.Database.Implementations;
 using Jellyfin.Server.Implementations.StorageHelpers;
 using Jellyfin.Server.Implementations.SystemBackupService;
 using MediaBrowser.Controller;
+using MediaBrowser.Controller.Library;
 using MediaBrowser.Controller.SystemBackupService;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore.Infrastructure;
@@ -33,6 +34,7 @@ public class BackupService : IBackupService
     private readonly IServerApplicationPaths _applicationPaths;
     private readonly IJellyfinDatabaseProvider _jellyfinDatabaseProvider;
     private readonly IHostApplicationLifetime _hostApplicationLifetime;
+    private readonly ILibraryManager _libraryManager;
     private static readonly JsonSerializerOptions _serializerSettings = new JsonSerializerOptions(JsonSerializerDefaults.General)
     {
         AllowTrailingCommas = true,
@@ -50,13 +52,15 @@ public class BackupService : IBackupService
     /// <param name="applicationPaths">The application paths.</param>
     /// <param name="jellyfinDatabaseProvider">The Jellyfin database Provider in use.</param>
     /// <param name="applicationLifetime">The SystemManager.</param>
+    /// <param name="libraryManager">Instance of the <see cref="ILibraryManager"/> interface.</param>
     public BackupService(
         ILogger<BackupService> logger,
         IDbContextFactory<JellyfinDbContext> dbProvider,
         IServerApplicationHost applicationHost,
         IServerApplicationPaths applicationPaths,
         IJellyfinDatabaseProvider jellyfinDatabaseProvider,
-        IHostApplicationLifetime applicationLifetime)
+        IHostApplicationLifetime applicationLifetime,
+        ILibraryManager libraryManager)
     {
         _logger = logger;
         _dbProvider = dbProvider;
@@ -64,6 +68,7 @@ public class BackupService : IBackupService
         _applicationPaths = applicationPaths;
         _jellyfinDatabaseProvider = jellyfinDatabaseProvider;
         _hostApplicationLifetime = applicationLifetime;
+        _libraryManager = libraryManager;
     }
 
     /// <inheritdoc/>
@@ -263,6 +268,14 @@ public class BackupService : IBackupService
     /// <inheritdoc/>
     public async Task<BackupManifestDto> CreateBackupAsync(BackupOptionsDto backupOptions)
     {
+        // Creating a backup runs a database optimization and reads the entire database under a transaction, both of
+        // which heavily contend with an active library scan and could capture an inconsistent database state.
+        if (_libraryManager.IsScanRunning)
+        {
+            _logger.LogWarning("Cannot create a backup while a library scan is running.");
+            throw new InvalidOperationException("Cannot create a backup while a library scan is running. Please try again once the scan has finished.");
+        }
+
         var manifest = new BackupManifest()
         {
             DateCreated = DateTime.UtcNow,
@@ -346,18 +359,39 @@ public class BackupService : IBackupService
                                     jsonSerializer.WriteStartArray();
 
                                     var set = entityType.ValueFactory().ConfigureAwait(false);
-                                    await foreach (var item in set.ConfigureAwait(false))
+                                    var enumerator = set.GetAsyncEnumerator();
+                                    await using (enumerator)
                                     {
-                                        entities++;
-                                        try
-                                        {
-                                            using var document = JsonSerializer.SerializeToDocument(item, _serializerSettings);
-                                            document.WriteTo(jsonSerializer);
-                                        }
-                                        catch (Exception ex)
+                                        while (true)
                                         {
-                                            _logger.LogError(ex, "Could not load entity {Entity}", item);
-                                            throw;
+                                            bool hasNext;
+                                            try
+                                            {
+                                                hasNext = await enumerator.MoveNextAsync();
+                                            }
+                                            catch (Exception ex)
+                                            {
+                                                _logger.LogError(ex, "Could not read next entity of type {Table}, the underlying data appears to be corrupt. Skipping this row and continuing backup; the affected database row should be inspected and fixed manually", entityType.SourceName);
+                                                continue;
+                                            }
+
+                                            if (!hasNext)
+                                            {
+                                                break;
+                                            }
+
+                                            var item = enumerator.Current;
+                                            entities++;
+                                            try
+                                            {
+                                                using var document = JsonSerializer.SerializeToDocument(item, _serializerSettings);
+                                                document.WriteTo(jsonSerializer);
+                                            }
+                                            catch (Exception ex)
+                                            {
+                                                _logger.LogError(ex, "Could not load entity {Entity}", item);
+                                                throw;
+                                            }
                                         }
                                     }