CHANGES SINCE WINFSP 2023

• [FIX] Fixes a compatibility problem with certain AntiVirus products (e.g. Trend Micro).

• [FIX] Fixes a couple of rare BSODs on recent versions of Windows 11. See commitsa482183,a2cd697 for details.

• [FIX] Fixes a rare problem when usingNtCreateFile to perform relative opens on a network drive (see GitHub issue#561).

• [FIX] Fixes a racing issue with two processes competing to start the FSD discovered during testing.

CHANGES SINCE WINFSP 2023

• [FIX] Fixes a rare BSOD on recent versions of Windows. See commita482183 for details.

• [FIX] Fixes a rare problem when usingNtCreateFile to perform relative opens on a network drive (see GitHub issue#561).

• [FIX] Fixes a racing issue with two processes competing to start the FSD discovered during testing.

CHANGES SINCE WINFSP 2023

• [FIX] Fixes a rare BSOD on recent versions of Windows. See commita482183 for details.

• [FIX] Fixes a racing issue with two processes competing to start the FSD discovered during testing.

CHANGES SINCE WINFSP 2022.2

This release is a major version change for WinFsp (from 1.x to 2.x). There are no backwards incompatible API changes in this release, but nevertheless enough things change that warrant a version change.

The major new feature of this release is that it allows uninstallation and reinstallation of WinFspwithout reboot. Going forward installers namedwinfsp-2.x.y.msi can be uninstalled and reinstalled without reboot. Furthermore a later versionwinfsp-2.x.y.msi installer can be used to upgrade over an earlier versionwinfsp-2.x.y.msi installer. However note that awinfsp-2.x.y.msi installer cannot be used to upgrade over a legacywinfsp-1.x.y.msi installer; you will still need to uninstall the oldwinfsp-1.x.y.msi installer, potentially reboot and then install the newwinfsp-2.x.y.msi installer.

Changes visible to file system developers are listed below:

• WinFsp executable files are now installed by default in the directoryC:\Program Files (x86)\WinFsp\SxS\sxs.<InstanceID>\bin. The previous directoryC:\Program Files (x86)\WinFsp\bin is now a junction that points to the above directory.

• The WinFsp driver name is no longerwinfsp, but rather a name such aswinfsp+<InstanceID>. This means that managing the driver using thesc.exe utility is no longer as easy.

• Thefsptool utility has been updated with new commandslsdrv,load,unload andver. Thelsdrv,load andunload commands can be used to manage the driver from the command line. This is rarely necessary, but may be useful for troubleshooting purposes.

• Prior to this release the WinFsp driver would never unmount a file system volume unless the user mode file system requested the unmount. From this release onward it is possible for the WinFsp driver to unmount a file system volume, without a user mode file system request. This is to allow for the driver to be unloaded.

  A new operationDispatcherStopped has been added toFSP_FILE_SYSTEM_INTERFACE, which is sent after the file system volume has been unmounted and the file system dispatcher has been stopped. This can happen because of a user mode file system request viaFspFileSystemStopDispatcher or because of driver unload. TheDispatcherStopped operation includes aNormally parameter, which isTRUE for normal file system shutdown viaFspFileSystemStopDispatcher andFALSE otherwise.

  Native file systems that use theFspService infrastructure can use theFspFileSystemStopServiceIfNecessary API to handle theDispatcherStopped operation (see the MEMFS and NTPTFS samples). FUSE file systems get this functionality for free. .NET file systems that use theService class infrastructure also get this functionality for free.

• WinFsp now offers a .NET library that targets .NET Framework 3.5 (as before) and one that targets .NET Standard 2.0. This is due to work by@Noire001 in PR#451.

  • There is now a winfsp.net nuget package athttps://www.nuget.org/packages/winfsp.net

• FUSE now supports path components up to 255 characters long (previously it was 255 bytes). This is due to work by@zeho11 in PR#474.

  • The FUSE passthrough file systems have been updated to support long paths. This is also due to work by@zeho11.

• In some rare circumstances WinFsp file systems could report duplicate directory entries. This problem has been fixed. (GitHub issue#475.)

• The WinFsp symbols directory has been removed. If you are looking for WinFsp symbols you can find them athttps://github.com/winfsp/winfsp.sym

Contributors

CHANGES SINCE WINFSP 2022.2

This release is a major version change for WinFsp (from 1.x to 2.x). There are no backwards incompatible API changes in this release, but nevertheless enough things change that warrant a version change.

The major new feature of this release is that it allows uninstallation and reinstallation of WinFspwithout reboot. Going forward installers namedwinfsp-2.x.y.msi can be uninstalled and reinstalled without reboot. Furthermore a later versionwinfsp-2.x.y.msi installer can be used to upgrade over an earlier versionwinfsp-2.x.y.msi installer. However note that awinfsp-2.x.y.msi installer cannot be used to upgrade over a legacywinfsp-1.x.y.msi installer; you will still need to uninstall the oldwinfsp-1.x.y.msi installer, potentially reboot and then install the newwinfsp-2.x.y.msi installer.

Changes visible to file system developers are listed below:

• WinFsp executable files are now installed by default in the directoryC:\Program Files (x86)\WinFsp\SxS\sxs.<InstanceID>\bin. The previous directoryC:\Program Files (x86)\WinFsp\bin is now a junction that points to the above directory.

• The WinFsp driver name is no longerwinfsp, but rather a name such aswinfsp+<InstanceID>. This means that managing the driver using thesc.exe utility is no longer as easy.

• Thefsptool utility has been updated with new commandslsdrv,load,unload andver. Thelsdrv,load andunload commands can be used to manage the driver from the command line. This is rarely necessary, but may be useful for troubleshooting purposes.

• Prior to this release the WinFsp driver would never unmount a file system volume unless the user mode file system requested the unmount. From this release onward it is possible for the WinFsp driver to unmount a file system volume, without a user mode file system request. This is to allow for the driver to be unloaded.

  A new operationDispatcherStopped has been added toFSP_FILE_SYSTEM_INTERFACE, which is sent after the file system volume has been unmounted and the file system dispatcher has been stopped. This can happen because of a user mode file system request viaFspFileSystemStopDispatcher or because of driver unload. TheDispatcherStopped operation includes aNormally parameter, which isTRUE for normal file system shutdown viaFspFileSystemStopDispatcher andFALSE otherwise.

  Native file systems that use theFspService infrastructure can use theFspFileSystemStopServiceIfNecessary API to handle theDispatcherStopped operation (see the MEMFS and NTPTFS samples). FUSE file systems get this functionality for free. .NET file systems that use theService class infrastructure also get this functionality for free.

• WinFsp now offers a .NET library that targets .NET Framework 3.5 (as before) and one that targets .NET Standard 2.0. This is due to work by@Noire001 in PR#451.

  • There is now a winfsp.net nuget package athttps://www.nuget.org/packages/winfsp.net

• FUSE now supports path components up to 255 characters long (previously it was 255 bytes). This is due to work by@zeho11 in PR#474.

  • The FUSE passthrough file systems have been updated to support long paths. This is also due to work by@zeho11.

• In some rare circumstances WinFsp file systems could report duplicate directory entries. This problem has been fixed. (GitHub issue#475.)

• The WinFsp symbols directory has been removed. If you are looking for WinFsp symbols you can find them athttps://github.com/winfsp/winfsp.sym

Contributors

CHANGES SINCE WINFSP 2022.2

This release is a major version change for WinFsp (from 1.x to 2.x). There are no backwards incompatible API changes in this release, but nevertheless enough things change that warrant a version change.

The major new feature of this release is that it allows uninstallation and reinstallation of WinFspwithout reboot. Going forward installers namedwinfsp-2.x.y.msi can be uninstalled and reinstalled without reboot. Furthermore a later versionwinfsp-2.x.y.msi installer can be used to upgrade over an earlier versionwinfsp-2.x.y.msi installer. However note that awinfsp-2.x.y.msi installer cannot be used to upgrade over a legacywinfsp-1.x.y.msi installer; you will still need to uninstall the oldwinfsp-1.x.y.msi installer, potentially reboot and then install the newwinfsp-2.x.y.msi installer.

Changes visible to file system developers are listed below:

• WinFsp executable files are now installed by default in the directoryC:\Program Files (x86)\WinFsp\SxS\sxs.<InstanceID>\bin. The previous directoryC:\Program Files (x86)\WinFsp\bin is now a junction that points to the above directory.

• The WinFsp driver name is no longerwinfsp, but rather a name such aswinfsp+<InstanceID>. This means that managing the driver using thesc.exe utility is no longer as easy.

• Thefsptool utility has been updated with new commandslsdrv,load,unload andver. Thelsdrv,load andunload commands can be used to manage the driver from the command line. This is rarely necessary, but may be useful for troubleshooting purposes.

• Prior to this release the WinFsp driver would never unmount a file system volume unless the user mode file system requested the unmount. From this release onward it is possible for the WinFsp driver to unmount a file system volume, without a user mode file system request. This is to allow for the driver to be unloaded.

  A new operationDispatcherStopped has been added toFSP_FILE_SYSTEM_INTERFACE, which is sent after the file system volume has been unmounted and the file system dispatcher has been stopped. This can happen because of a user mode file system request viaFspFileSystemStopDispatcher or because of driver unload. TheDispatcherStopped operation includes aNormally parameter, which isTRUE for normal file system shutdown viaFspFileSystemStopDispatcher andFALSE otherwise.

  Native file systems that use theFspService infrastructure can use theFspFileSystemStopServiceIfNecessary API to handle theDispatcherStopped operation (see the MEMFS and NTPTFS samples). FUSE file systems get this functionality for free. .NET file systems that use theService class infrastructure also get this functionality for free.

• WinFsp now offers a .NET library that targets .NET Framework 3.5 (as before) and one that targets .NET Standard 2.0. This is due to work by@Noire001 in PR#451.

  • There is now a winfsp.net nuget package athttps://www.nuget.org/packages/winfsp.net

• FUSE now supports path components up to 255 characters long (previously it was 255 bytes). This is due to work by@zeho11 in PR#474.

  • The FUSE passthrough file systems have been updated to support long paths. This is also due to work by@zeho11.

• The WinFsp symbols directory has been removed. If you are looking for WinFsp symbols you can find them athttps://github.com/winfsp/winfsp.sym

Contributors

CHANGES SINCE WINFSP 2022+ARM64

Note: This release (2022.2 Update1) is the same as the previous release (2022.2) except that: (1) the kernel-mode drivers are now digitally signed only with the Microsoft Attestation signature, and that: (2) no release assets are digitally signed with SHA-1. (This change was necessary to fix a problem in older versions of Windows such as Windows 7.)

• [NEW] WinFsp now supports mounting as directory using the Mount Manager. Use the syntax\\.\C:\Path\To\Mount\Directory.

• [NEW] A new registry settingMountUseMountmgrFromFSD has been added. SeeWinFsp Registry Settings for details.

• [FIX] A problem with Windows containers has been fixed. (GitHub issue#438.)

• [FIX] File systems can now be mounted as directories on ARM64. (GitHub issue#448.)

• [FIX] The passthrough file system now reports correctIndexNumber. (GitHub issue#325.)

• [BUILD] Product configuration for the relative paths to the File System Driver, Network Provider and EventLog is now possible via the filebuild.version.props located inbuild\VStudio.

CHANGES SINCE WINFSP 2022.2

This release is a major version change for WinFsp (from 1.x to 2.x). There are no backwards incompatible API changes in this release, but nevertheless enough things change that warrant a version change.

The major new feature of this release is that it allows uninstallation and reinstallation of WinFspwithout reboot. Going forward installers namedwinfsp-2.x.y.msi can be uninstalled and reinstalled without reboot. Furthermore a later versionwinfsp-2.x.y.msi installer can be used to upgrade over an earlier versionwinfsp-2.x.y.msi installer. However note that awinfsp-2.x.y.msi installer cannot be used to upgrade over a legacywinfsp-1.x.y.msi installer; you will still need to uninstall the oldwinfsp-1.x.y.msi installer, potentially reboot and then install the newwinfsp-2.x.y.msi installer.

Some changes that may be visible to file system developers are listed below:

• WinFsp executable files are now installed by default in the directoryC:\Program Files (x86)\WinFsp\SxS\sxs.<InstanceID>\bin. The previous directoryC:\Program Files (x86)\WinFsp\bin is now a junction that points to the above directory.

• The WinFsp driver name is no longerwinfsp, but rather a name such aswinfsp+<InstanceID>. This means that managing the driver using thesc.exe utility is no longer as easy.

• Thefsptool utility has been updated with new commandslsdrv,load,unload andver. Thelsdrv,load andunload commands can be used to manage the driver from the command line. This is rarely necessary, but may be useful for troubleshooting purposes.

• The WinFsp symbols directory has been removed. If you are looking for WinFsp symbols you can find them athttps://github.com/winfsp/winfsp.sym

This release introduces significant internal changes, including kernel mode changes to enable the driver to be unloaded. Although there are no known crashes or other problems of such severity, please do not use in production environments.

VirusTotal Scan Results

CHANGES SINCE WINFSP 2022+ARM64

• [NEW] WinFsp now supports mounting as directory using the Mount Manager. Use the syntax\\.\C:\Path\To\Mount\Directory.

• [NEW] A new registry settingMountUseMountmgrFromFSD has been added. SeeWinFsp Registry Settings for details.

• [FIX] A problem with Windows containers has been fixed. (GitHub issue#438.)

• [FIX] File systems can now be mounted as directories on ARM64. (GitHub issue#448.)

• [FIX] The passthrough file system now reports correctIndexNumber. (GitHub issue#325.)

• [BUILD] Product configuration for the relative paths to the File System Driver, Network Provider and EventLog is now possible via the filebuild.version.props located inbuild\VStudio.

VirusTotal Scan Results

CHANGES SINCE WINFSP 2022+ARM64

• [NEW] WinFsp now supports mounting as directory using the Mount Manager. Use the syntax\\.\C:\Path\To\Mount\Directory.

• [NEW] A new registry settingMountUseMountmgrFromFSD has been added. SeeWinFsp Registry Settings for details.

• [FIX] A problem with Windows containers has been fixed. (GitHub issue#438.)

• [FIX] File systems can now be mounted as directories on ARM64. (GitHub issue#448.)

• [FIX] The passthrough file system now reports correctIndexNumber. (GitHub issue#325.)

• [BUILD] Product configuration for the relative paths to the File System Driver, Network Provider and EventLog is now possible via the filebuild.version.props located inbuild\VStudio.