Fixed: File imports on cloud drives slow due to transaction logic

src/NzbDrone.Common.Test/DiskTests/DiskTransferServiceFixture.cs

@@ -21,15 +21,37 @@ namespace NzbDrone.Common.Test.DiskTests
         private readonly string _tempTargetPath = @"C:\target\my.video.mkv.partial~".AsOsAgnostic();
         private readonly string _nfsFile = ".nfs01231232";
 
+        private MockMount _sourceMount;
+        private MockMount _targetMount;
+
         [SetUp]
         public void SetUp()
         {
             Mocker.GetMock<IDiskProvider>(MockBehavior.Strict);
 
+            _sourceMount = new MockMount()
+            {
+                Name = "source",
+                RootDirectory = @"C:\source".AsOsAgnostic()
+            };
+            _targetMount = new MockMount()
+            {
+                Name = "target",
+                RootDirectory = @"C:\target".AsOsAgnostic()
+            };
+
             Mocker.GetMock<IDiskProvider>()
                 .Setup(v => v.GetMount(It.IsAny<string>()))
                 .Returns((IMount)null);
 
+            Mocker.GetMock<IDiskProvider>()
+                .Setup(v => v.GetMount(It.Is<string>(p => p.StartsWith(_sourceMount.RootDirectory))))
+                .Returns(_sourceMount);
+
+            Mocker.GetMock<IDiskProvider>()
+                .Setup(v => v.GetMount(It.Is<string>(p => p.StartsWith(_targetMount.RootDirectory))))
+                .Returns(_targetMount);
+
             WithEmulatedDiskProvider();
 
             WithExistingFile(_sourcePath);
@@ -59,6 +81,27 @@ namespace NzbDrone.Common.Test.DiskTests
                 .Verify(v => v.MoveFile(_sourcePath, _targetPath, false), Times.Once());
         }
 
+        [TestCase("fuse.mergerfs")]
+        [TestCase("fuse.rclone")]
+        [TestCase("mergerfs")]
+        [TestCase("rclone")]
+        public void should_not_use_verified_transfer_on_specific_filesystems(string fs)
+        {
+            MonoOnly();
+            
+            _targetMount.DriveFormat = fs;
+
+            Subject.VerificationMode.Should().Be(DiskTransferVerificationMode.VerifyOnly);
+
+            var result = Subject.TransferFile(_sourcePath, _targetPath, TransferMode.Move);
+
+            Mocker.GetMock<IDiskProvider>()
+                .Verify(v => v.TryCreateHardLink(_sourcePath, _backupPath), Times.Never());
+
+            Mocker.GetMock<IDiskProvider>()
+                .Verify(v => v.MoveFile(_sourcePath, _targetPath, false), Times.Once());
+        }
+
         [Test]
         public void should_throw_if_path_is_the_same()
         {

src/NzbDrone.Common.Test/DiskTests/MockMount.cs

@@ -0,0 +1,30 @@
+using System.IO;
+using NzbDrone.Common.Disk;
+
+namespace NzbDrone.Common.Test.DiskTests
+{
+    public class MockMount : IMount
+    {
+        public long AvailableFreeSpace { get; set; }
+
+        public string DriveFormat { get; set; }
+
+        public DriveType DriveType { get; set; } = DriveType.Fixed;
+
+        public bool IsReady { get; set; } = true;
+
+        public MountOptions MountOptions { get; set; }
+
+        public string Name { get; set; }
+
+        public string RootDirectory { get; set; }
+
+        public long TotalFreeSpace { get; set; }
+
+        public long TotalSize { get; set; }
+
+        public string VolumeLabel { get; set; }
+
+        public string VolumeName { get; set; }
+    }
+}

src/NzbDrone.Common/Disk/DiskTransferService.cs

@@ -307,15 +307,31 @@ namespace NzbDrone.Common.Disk
                 }
             }
 
-            // We force a transactional transfer if the transfer occurs between mounts and one of the mounts is cifs, it would be a copy anyway.
+            // Adjust the transfer mode depending on the filesystems
-            if (verificationMode == DiskTransferVerificationMode.TryTransactional && OsInfo.IsNotWindows)
+            if (verificationMode == DiskTransferVerificationMode.TryTransactional)
             {
                 var sourceMount = _diskProvider.GetMount(sourcePath);
                 var targetMount = _diskProvider.GetMount(targetPath);
 
-                if (sourceMount != null && targetMount != null && sourceMount.RootDirectory != targetMount.RootDirectory &&
+                var isSameMount = sourceMount != null && targetMount != null && sourceMount.RootDirectory == targetMount.RootDirectory;
-                    (sourceMount.DriveFormat == "cifs" || targetMount.DriveFormat == "cifs"))
+
+                var sourceDriveFormat = sourceMount?.DriveFormat ?? string.Empty;
+                var targetDriveFormat = targetMount?.DriveFormat ?? string.Empty;
+
+                if (isSameMount)
+                {
+                    // No transaction needed for operations on same mount, force VerifyOnly
+                    verificationMode = DiskTransferVerificationMode.VerifyOnly;
+                }
+                else if (sourceDriveFormat.Contains("mergerfs") || sourceDriveFormat.Contains("rclone") ||
+                         targetDriveFormat.Contains("mergerfs") || targetDriveFormat.Contains("rclone"))
+                {
+                    // Cloud storage filesystems don't need any Transactional stuff and it hurts performance, force VerifyOnly
+                    verificationMode = DiskTransferVerificationMode.VerifyOnly;
+                }
+                else if ((sourceDriveFormat == "cifs" || targetDriveFormat == "cifs") && OsInfo.IsNotWindows)
                 {
+                    // Force Transactional on a cifs mount due to the likeliness of move failures on certain scenario's on mono
                     verificationMode = DiskTransferVerificationMode.Transactional;
                 }
             }