The free OSR Learning Library has more than 50 articles on a wide variety of topics about writing and debugging device drivers and Minifilters. From introductory level to advanced. All the articles have been recently reviewed and updated, and are written using the clear and definitive style you've come to expect from OSR over the years.
Check out The OSR Learning Library at: https://www.osr.com/osr-learning-library/
In NT Insider article "Tracking State and Context - Reference Counting for File System Filter Drivers" there is sentence "For each IRP_MJ_CLOSE the filter driver decrements the reference count on the per-file context structure if the FO_STREAM_FILE bit is not set for the file object and if CcGetFileObjectFromSectionPtrs does not return this file object."
I don't understand why we should call CcGetFileObjectFromSectionPtrs.
If this file is being closed then it can't be used for caching. Not anymore. So if we got irp_mj_close we already know that this file is not used for caching.
If the file still being used for caching then we won't get irp_mj_close.
|Upcoming OSR Seminars|
|OSR has suspended in-person seminars due to the Covid-19 outbreak. But, don't miss your training! Attend via the internet instead!|
|Writing WDF Drivers||7 Dec 2020||LIVE ONLINE|
|Internals & Software Drivers||25 Jan 2021||LIVE ONLINE|
|Developing Minifilters||8 March 2021||LIVE ONLINE|