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Changed: Cap directory scan recursion instead of skipping reparse points
The scanner now follows all reparse points (junctions, symlinks, cloud placeholders) as normal directories. Infinite recursion via junction cycles is bounded by a hard depth cap (256) in GetFilesEx, matching how .NET's EnumerationOptions handles it. This replaces the name-surrogate reparse-point check, which ran CreateFileW + DeviceIoControl per reparse-pointed directory and caused OneDrive/cloud files to be skipped (#882).
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Lines changed: 32 additions & 92 deletions

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‎changelog-template.hbs‎

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@@ -3,29 +3,34 @@
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# 1.30.2: Cloud Storage & Wine Improvements
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## Generalize Cloud Folder Detection Beyond OneDrive
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## Fix Broken File Detection in OneDrive Folders
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The fast hand-rolled directory scanner previously accidentally skipped some
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contents of OneDrive cloud folders.
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The directory scanner (file search) skipped symlinks for 'offline' (non-local) files.
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Previously in Reloaded-II, we skipped resolving Symlinks in the `Mods` folder;
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and symlinks to 'offline' files (not on current machine).
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> The file is offline. The data of the file is not immediately available.
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> [FileAttributes.Offline](https://learn.microsoft.com/en-us/dotnet/api/system.io.fileattributes?view=net-10.0#fields)
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Turns out- files under OneDrive can classify as symlinks- so in some cases- they
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were just not being picked up. Unfortunately- optimizations here have backfired.
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A younger me, half a decade ago misunderstood this to mean as
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'this file cannot be accessed' or 'on a server, but you're offline'.
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Coincidentally, [Opst34](https://github.com/Reloaded-Project/Reloaded-II/issues/882) ran into
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an issue where they couldn't configure their mod- due to the OneDrive sync feature; which
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is how I found out.
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This was not correct- what it rather means is, if you try to read the data; it will
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fetch it from the cloud rather than local storage. This means that if a file is
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on cloud, but not on local storage; we would not recognise it.
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This may have been the culprit of the infamous endless update loop some folks experienced
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when inside OneDrive.
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[Opst34](https://github.com/Reloaded-Project/Reloaded-II/issues/882) reported a mod that
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could not be configured due to the OneDrive sync feature.
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In any case, we now separate symlinks and cloud storage folders apart, to best
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of ability.
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Over the years, this may also have caused the infamous endless update loop some
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users saw inside OneDrive.
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In reality, we probably should just allow all files- but this was the most painless
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fix (for now).
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The scanner no longer ignores these files. Just in case, infinite recursion is also handled,
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by a hard recursion-depth cap (256). So if you got cyclic symlinks like
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`C:\Reloaded-II\Mods\Loop\Loop\Loop\...`, it will stop after 256 iterations rather
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than hanging.
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Detection of cloud storage also updated; since users who have installed Windows
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without OneDrive enabled, and then opted into it later would not be caught. This
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however wasn't well tested; but should not cause regression in worse case.
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## Only Write `steamappid.txt` File When Correct ID Is Obtained by @datasone0
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‎source/Reloaded.Mod.Loader.IO/Utility/IOEx.cs‎

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@@ -4,6 +4,13 @@ public static class IOEx
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{
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private static readonly char[] InvalidFilePathChars = Path.GetInvalidPathChars().Union(Path.GetInvalidFileNameChars()).ToArray();
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/// <summary>
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/// Hard ceiling on recursion depth to prevent infinite loops via reparse point
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/// (junction/symlink) cycles, since the runtime follows reparse points without
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/// cycle detection. 256 is well above any legitimate mod directory depth.
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/// </summary>
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private const int MaxRecursionDepthCap = 256;
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/// <summary>
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/// Moves a directory from a given source path to a target path, overwriting all files.
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/// </summary>
@@ -175,6 +182,7 @@ public static bool CheckFileAccess(string filePath, FileMode mode = FileMode.Ope
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/// <param name="recurseOnFound">Continues to search in subdirectories even if <see cref="fileName"/> is found.</param>
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public static List<string> GetFilesEx(string directory, string fileName, int maxDepth = 1, int minDepth = 1, bool recurseOnFound = true)
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{
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maxDepth = Math.Min(maxDepth, MaxRecursionDepthCap);
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var files = new List<string>();
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if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))

‎source/Reloaded.Mod.Loader.IO/Utility/Windows/WindowsDirectorySearcher.cs‎

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@@ -181,14 +181,9 @@ public static unsafe bool TryGetDirectoryContents_Internal(string dirPath, List<
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var isDirectory = (info->FileAttributes & FileAttributes.Directory) > 0;
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// Skip symlinks/junctions that point elsewhere (prevents infinite recursion).
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// Cloud folders (e.g. OneDrive) use different reparse tags, so they are
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// treated as normal directories and enumerated. Only checked for directories;
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// files with reparse points are always enumerated.
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if (isDirectory && (info->FileAttributes & FileAttributes.ReparsePoint) != 0 &&
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IsNameSurrogateReparsePoint($@"{originalDirPath}\{fileName}"))
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goto nextfile;
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// Reparse points (junctions/symlinks/cloud placeholders) are followed as
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// normal directories. Infinite recursion via junction cycles is bounded by
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// a recursion-depth cap in the caller (IOEx.GetFilesEx).
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if (isDirectory)
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{
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directories.Add(new DirectoryInformation
@@ -222,63 +217,6 @@ public static unsafe bool TryGetDirectoryContents_Internal(string dirPath, List<
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return true;
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}
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/// <summary>
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/// Returns true if the reparse point at <paramref name="fullPath"/> is a 'name surrogate'
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/// (a symlink or junction/mount-point that redirects the path). Such entries are skipped
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/// during enumeration to prevent following them into cycles.
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///
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/// Cloud providers (e.g. OneDrive) also use reparse points on real, locally-available
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/// folders; those tags do not carry the name-surrogate bit, so this returns false for them
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/// and the directory is enumerated normally.
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///
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/// On any failure to determine the tag we conservatively return false (do not skip), since
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/// wrongly skipping a real directory is the original bug this guards against. A genuine
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/// symlink whose tag cannot be read would still be bounded by <c>maxDepth</c>.
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/// </summary>
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private static unsafe bool IsNameSurrogateReparsePoint(string fullPath)
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{
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const uint FSCTL_GET_REPARSE_POINT = 0x000900A8;
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// Bit set in the reparse tag of entries that substitute/redirect the name
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// (symlinks, junctions/mount-points). Cloud reparse tags do not set this bit.
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const uint REPARSE_TAG_NAME_SURROGATE = 0x20000000;
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const uint GENERIC_READ = 0x80000000;
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const uint FILE_SHARE_READ = 0x00000001;
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const uint FILE_SHARE_WRITE = 0x00000002;
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const uint OPEN_EXISTING = 3;
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// BACKUP_SEMANTICS allows opening directories; OPEN_REPARSE_POINT opens the
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// reparse entry itself instead of resolving through it.
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const uint FILE_FLAG_BACKUP_SEMANTICS = 0x02000000;
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const uint FILE_FLAG_OPEN_REPARSE_POINT = 0x00200000;
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const int BufferSize = 1024 * 16;
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var handle = CreateFileW(fullPath, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE,
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IntPtr.Zero, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OPEN_REPARSE_POINT, IntPtr.Zero);
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if (handle == new IntPtr(-1))
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return false;
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try
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{
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byte* buffer = stackalloc byte[BufferSize];
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if (!DeviceIoControl(handle, FSCTL_GET_REPARSE_POINT, IntPtr.Zero, 0,
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(IntPtr)buffer, BufferSize, out _, IntPtr.Zero))
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{
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return false;
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}
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// REPARSE_DATA_BUFFER.ReparseTag is the first DWORD.
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return (*(uint*)buffer & REPARSE_TAG_NAME_SURROGATE) != 0;
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}
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finally
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{
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CloseHandle(handle);
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}
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}
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internal struct MultithreadedDirectorySearcher : IDisposable
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{
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private Thread[] _threads;
@@ -376,17 +314,6 @@ public void Dispose()
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[DllImport("kernel32.dll", CharSet = CharSet.Ansi)]
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static extern IntPtr GetProcAddress(IntPtr hModule, string procName);
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[DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
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internal static extern IntPtr CreateFileW(string lpFileName, uint dwDesiredAccess, uint dwShareMode, IntPtr lpSecurityAttributes, uint dwCreationDisposition, uint dwFlagsAndAttributes, IntPtr hTemplateFile);
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[DllImport("kernel32.dll", SetLastError = true)]
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[return: MarshalAs(UnmanagedType.Bool)]
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internal static extern bool DeviceIoControl(IntPtr hDevice, uint dwIoControlCode, IntPtr lpInBuffer, uint nInBufferSize, IntPtr lpOutBuffer, uint nOutBufferSize, out uint lpBytesReturned, IntPtr lpOverlapped);
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[DllImport("kernel32.dll", SetLastError = true)]
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[return: MarshalAs(UnmanagedType.Bool)]
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internal static extern bool CloseHandle(IntPtr hObject);
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#endregion
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#region Native Import Wrappers

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