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File system mini-filter drivers vs storage filter drivers RRS feed

  • Question

  • I'm reading here https://docs.microsoft.com/en-us/windows-hardware/drivers/ifs/attaching-a-filter-to-a-file-system-or-volume ( this is probably about legacy file system drivers)

    "File system filter drivers can attach to, and filter I/O for, any file system volume. They cannot attach directly to storage devices, such as disk drives or partitions. Also, they cannot attach to individual directories or files."

    What about mini-filters? Can they attach to disk drives or I will need storage filter driver for this?

    From what I understood my mini-filter driver will be an upper-filter?

    If mini-filters can attach to disk drives then what will be higher, file system mini-filters or storage filter drivers?

    Thanks in advance! and happy new year to ya all! :) 

    Tuesday, December 26, 2017 10:39 AM

Answers

  • Mini-filters are File System Filters, they are not designed to work at the disk level, but instead reside above the file system level.   Basically the file system stack consists of:

    1. File System Driver
    2. Volume Driver
    3. Disk Driver
    4. Storport driver (i.e. the actual hardware)

    Each of those drivers can have filters.


    Don Burn Windows Driver Consulting Website: http://www.windrvr.com

    • Marked as answer by James Danks Tuesday, December 26, 2017 2:14 PM
    Tuesday, December 26, 2017 12:54 PM

All replies

  • Mini-filters are File System Filters, they are not designed to work at the disk level, but instead reside above the file system level.   Basically the file system stack consists of:

    1. File System Driver
    2. Volume Driver
    3. Disk Driver
    4. Storport driver (i.e. the actual hardware)

    Each of those drivers can have filters.


    Don Burn Windows Driver Consulting Website: http://www.windrvr.com

    • Marked as answer by James Danks Tuesday, December 26, 2017 2:14 PM
    Tuesday, December 26, 2017 12:54 PM
  • Documentation of legacy file system filter drivers says that it's only possible to attach to volume only so I assumed it is so for mini-filters too. So it seems they're pretty similar to upper-level storage filter drivers. 

    https://docs.microsoft.com/en-us/windows-hardware/drivers/kernel/images/drvlyr.png

    • Edited by James Danks Tuesday, December 26, 2017 2:11 PM
    Tuesday, December 26, 2017 2:09 PM
  • Mini-filters run in a legacy filter driver.    The illustration you show is actually only accurate for any one of the four layers I mention above.  There should have been a 5th layer of the bus driver, but I dropped that.


    Don Burn Windows Driver Consulting Website: http://www.windrvr.com

    Tuesday, December 26, 2017 2:31 PM