Always getting DOKAN_START_ERROR

[uhonermann]

Hello,

I have a system here where I always get DOKAN_START_ERROR on mount.
This is reproducable with the memfs sample (memfs.exe /l K: /d /e).
There's no other output than this error, the only other thing I can see is some output in the eventlog:

20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: Mount entry found: \DosDevices\R: -> \Device\Volume{d6cc17c5-1734-4085-bce7-964f1e9f5de9}
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: Found entry with matching mount point.
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: Finding mount entry; lockGlobal = 1; mount point = \DosDevices\R:.
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: Finished event start with status 3 and flags: 11
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: Returning actual mount point R
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: Mount point was still not assigned after forcing.
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: IOCTL_MOUNTMGR_CREATE_POINT succeeded.
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: -964f1e9f5de9}".
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: Creating mount point: "\DosDevices\R:" for device name: "\Device\Volume{d6cc17c5-1734-4085-bce7
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: Warning: mount point creation is being forced.
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: Event start using mount ID: 1; device name: \Volume{d6cc17c5-1734-4085-bce7-964f1e9f5de9}.
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: Inserted new mount entry.
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: ume{d6cc17c5-1734-4085-bce7-964f1e9f5de9}" created
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: SymbolicLink: "\DosDevices\Global\Volume{d6cc17c5-1734-4085-bce7-964f1e9f5de9}" -> "\Device\Vol
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: ; type: 8
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: \DosDevices\Global\Volume{d6cc17c5-1734-4085-bce7-964f1e9f5de9}"; mount point: "\DosDevices\R:"
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: disk device name: "\Device\Volume{d6cc17c5-1734-4085-bce7-964f1e9f5de9}"; symbolic link name: "
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: Creating disk device; mount point = R; mount ID = 1l
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: No mount entry found.
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: Finding mount entry; lockGlobal = 0; mount point = \DosDevices\R:.
20231013 18:31:43 ID:00001 (0x40060001) VWDGF - INFO - Src: dokan2 Desc: Entered event start.

It looks like IoVerifyVolume doesn't trigger DokanMountVolume for some reason, but why ?

Regards,
Uwe

[Liryna]

Hi @uhonermann ,

It is possible that Mount manager auto mount was disabled on the system and thats why the driver letter was not assigned automatically.

Dokan disable it temporarily for mount point folder.

dokany/sys/util/mountmgr.c

Lines 254 to 280 in b8056db

	NTSTATUS DokanQueryAutoMount(PBOOLEAN State) {
	NTSTATUS status;
	MOUNTMGR_QUERY_AUTO_MOUNT queryAutoMount;
	status =
	DokanSendIoContlToMountManager(IOCTL_MOUNTMGR_QUERY_AUTO_MOUNT, NULL, 0,
	&queryAutoMount, sizeof(queryAutoMount));
	if (NT_SUCCESS(status)) {
	DOKAN_LOG_("CurrentState: %d", queryAutoMount.CurrentState);
	*State = queryAutoMount.CurrentState;
	}
	return status;
	}
	NTSTATUS DokanSendAutoMount(BOOLEAN State) {
	NTSTATUS status;
	MOUNTMGR_SET_AUTO_MOUNT setAutoMount;
	setAutoMount.NewState = State;
	DOKAN_LOG_("State %d", setAutoMount.NewState);
	status = DokanSendIoContlToMountManager(IOCTL_MOUNTMGR_SET_AUTO_MOUNT,
	&setAutoMount, sizeof(setAutoMount),
	NULL, 0);
	return status;
	}

[uhonermann]

Hi Liryna,

thank you, I'll check that.

Regards,
Uwe

[uhonermann]

I checked that, AutoMount is enabled:

[Liryna]

Then there must be a software on the computer blocking the request to reach dokan driver. It could be an antivirus or other of such types of drivers.