Hello Neal,
I was going to block them with events in the filter’s dispatch
routine. I.e. notify my user-space application to copy the file and
wait for event. After the file is copied the user-space application
sets the event.
I decided to do so because I don’t want the request to be completed by
FSD before I backup the file.
–
Roman Kudinov
Wednesday, August 4, 2004, 8:27:46 PM, you wrote:
NC> Do you mean blocking it by failing the write or by pending the write for
NC> a period of time? Failing it has problems as Maxim pointed out.
NC> Pending the write is reasonable as long as you don’t pend it for too
NC> long and make the IRP cancelable. I would also be concerned if you are
NC> doing this for a large number of files at the same time as you might
NC> deadlock the system.
NC> If you are going to do this I would recommend that you use the cancel
NC> safe queue support provided by the kernel.
NC> Neal Christiansen
NC> Microsoft File System Filter Group Lead
NC> This posting is provided “AS IS” with no warranties, and confers no
NC> rights.
NC> -----Original Message-----
NC> From: xxxxx@lists.osr.com
NC> [mailto:xxxxx@lists.osr.com] On Behalf Of Roman Kudinov
NC> Sent: Monday, July 26, 2004 12:49 AM
NC> To: Windows File Systems Devs Interest List
NC> Subject: Re[2]: [ntfsd] Fast I/O &. IRP_MJ_xxx
>> However I need to block I/O operations which can modify information
>> on disk on some conditions for a particular period of time.
MSS>> Block CREATE requests which ask for write access. This is the only
NC> really
MSS>> possible mean of achieving this task.
NC> Unfortunately a file can be opened already at the moment I need to
NC> block it.
NC> Is there any danger in blocking of IRP_MJ_WRITE request? I tried to
NC> do it and in test mode it worked fine. But I can suppose that issues
NC> may appear when it will work with real file operations with caching
NC> and so on.