Add FileSystemHost.Notify for kernel cache invalidation#1
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Adds FspFileSystemNotify P/Invoke + FspFsctlNotifyInfo struct + FileNotify constants + public FileSystemHost.Notify(filter, action, fileName) so user-mode file systems can invalidate the WinFsp kernel FileInfo cache after path-mutating operations (rename, delete, overwrite, create, set-size, set-attrs). Required for correctness when FileInfoTimeout is large or uint.MaxValue — otherwise the kernel can serve stale Open/Read results from cache without consulting user-mode. Concrete failure: leveldb's atomic-rename pattern reads zero bytes from a freshly-renamed CURRENT file, breaking every Chromium leveldb component (Local Storage, GCM Store, Sync Data, ...). Also adds FileOperationInfo.FileName so callbacks like OverwriteFile (whose IFileSystem signature does not include a path parameter) can issue Notify without storing the path on Context themselves. Bumped to 0.1.2-pre.2. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
xUnit's IClassFixture<T> creates one fixture instance per test class.
NotifyTests + SyncTests both used IClassFixture<SyncFixture>, so xUnit
instantiated SyncFixture twice in the same process — the second mount
collided on the same UNC prefix and failed STATUS_OBJECT_NAME_COLLISION
(0x80070050).
Switching to [CollectionDefinition] / [Collection("Sync")] makes the fixture
shared across both classes — one mount, run all tests, one unmount.
The same pattern is applied to SyncCompleted and TrueAsync for consistency.
Did not surface locally because NotifyTests was usually filtered to run
alone; on CI the full suite runs and exposed the collision.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
hooyao
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May 3, 2026
v0.1.2-pre.2 tag was pushed before PR review, and the early CI failure (fixture collision now fixed in #1) prevented the release workflow from publishing. Cutting a fresh pre-release from merged main so the published package corresponds to a green commit. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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Summary
FspFileSystemNotifyP/Invoke +FspFsctlNotifyInfostruct (12-byte, matches thestatic_assertinwinfsp/fsctl.h)FileNotifyconstants class (Change*filters,Action*actions) — values cross-checked againstWinNT.hFileSystemHost.Notify(filter, action, fileName)— stack-allocated buffer (≤ 4 KB),ArrayPoolfallback for longer paths, returns NTSTATUS unchangedfuse.creference implementation)FileOperationInfo.FileNameso callbacks likeOverwriteFile(whoseIFileSystemsignature has no path parameter) can issueNotifywithout storing the path onContextthemselvesNotifyTests(struct size, packing, case sensitivity, oversized rejection, constants)Why
User-mode file systems built on this binding could not invalidate the WinFsp kernel
FileInfocache after path-mutating operations — because the actualFspFileSystemNotifyAPI was not exposed in the binding (only the unusedBegin/Endframing was). Concrete failure: leveldb's atomic-rename pattern reads zero bytes from a freshly-renamedCURRENTfile whenFileInfoTimeout > 0, breaking every Chromium leveldb component (Local Storage, GCM Store, Sync Data, Site Characteristics Database, …).The downstream RamDrive change that consumes this API is at https://github.com/hooyao/RamDrive (PR will follow after this one merges and the package is published to NuGet).
Version bumped to
0.1.2-pre.2and taggedv0.1.2-pre.2.Test plan
dotnet test tests/WinFsp.Native.Tests --filter NotifyTests— 5/5 passFileSystemHostTestsstill pass (no regression in TestMemFs fixture)dotnet pack -c Release -o ./artifactsproducesWinFsp.Native.0.1.2-pre.2.nupkg🤖 Generated with Claude Code