Refactored a bit, added comments on the file systems.

LightlessSync/Utils/FileSystemHelper.cs

@@ -8,15 +8,15 @@ namespace LightlessSync.Utils
         public enum FilesystemType
         {
             Unknown = 0,
-            NTFS, // Compressable
-            Btrfs, // Compressable
-            Ext4,
-            Xfs,
-            Apfs,
-            HfsPlus,
-            Fat,
-            Exfat,
-            Zfs // Compressable
+            NTFS, // Compressable on file level
+            Btrfs, // Compressable on file level
+            Ext4, // Uncompressable
+            Xfs, // Uncompressable
+            Apfs, // Compressable on OS
+            HfsPlus, // Compressable on OS
+            Fat, // Uncompressable
+            Exfat, // Uncompressable
+            Zfs // Compressable, not on file level
         }
 
         private const string _mountPath = "/proc/mounts";
@@ -105,6 +105,40 @@ namespace LightlessSync.Utils
             }
         }
 
+        public static string GetMountOptionsForPath(string path)
+        {
+            try
+            {
+                var fullPath = Path.GetFullPath(path);
+                var mounts = File.ReadAllLines("/proc/mounts");
+                string bestMount = string.Empty;
+                string mountOptions = string.Empty;
+
+                foreach (var line in mounts)
+                {
+                    var parts = line.Split(' ');
+                    if (parts.Length < 4) continue;
+                    var mountPoint = parts[1].Replace("\\040", " ", StringComparison.Ordinal);
+                    string normalized;
+                    try { normalized = Path.GetFullPath(mountPoint); }
+                    catch { normalized = mountPoint; }
+
+                    if (fullPath.StartsWith(normalized, StringComparison.Ordinal) &&
+                        normalized.Length > bestMount.Length)
+                    {
+                        bestMount = normalized;
+                        mountOptions = parts[3];
+                    }
+                }
+
+                return mountOptions;
+            }
+            catch (Exception ex)
+            {
+                return string.Empty;
+            }
+        }
+
         private static FilesystemType GetLinuxFilesystemType(string filePath)
         {
             try