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How can I retrieve the disk offset to where a PFAST_IO_WRITE is being sent to?

sbhatsbhat Member Posts: 2

I am writing a filter driver where I have implemented all possible IRPs like IRP_MJ_CREATE IRP_MJ_READ etc. I started implementing fast io routines also in this driver. I am required to fetch the details of disk offset where the writes are targeted to. With irps, I could get the details from irp parameter in the routines. But when implementing fastio , I am stuck at finding the disk offset. Any reads or pointers in this directions would be helpful.


  • Scott_Noone_(OSR)Scott_Noone_(OSR) Administrator Posts: 3,590

    Sorry, I'm confused...

    Are you writing a file system filter, a disk filter, or a volume filter? The file system uses Fast I/O for reads/writes and the file offset is a parameter. There's no concept of fast I/O read/write at the disk or volume levels.


  • sbhatsbhat Member Posts: 2

    Right! I am writing a volume filter driver and was thinking fast I/O concepts come in volume level too. Now its clear to me. Thanks for the lead.

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