EldoS | Feel safer!

Software components for data protection, secure storage and transfer

Question about read file

Posted: 02/06/2013 10:40:17
by Davide Baccaglini (Standard support level)
Joined: 11/19/2012
Posts: 48

Hello, I've a question about read file.

Using ProcessMonitor I see that the operating system manages 2 type of reading events: IRP_MJ_READ and FASTIO_READ. With CBFS which type of event is managed?

Thanks in advance,
Posted: 02/06/2013 11:49:02
by Volodymyr Zinin (Team)

Both types are used. But the second one is "fast I/O" request. In order to accelerate I/O the system often sends it first to file systems. And if the file data is cached then the request finished quickly (in the case of CallbackFS it's processed internally by the driver without calling of the OnReadFile callback). In the other case the "fast I/O" request returns FALSE and Windows sends "usual" request (IRP_MJ_READ), which in the case of CallbackFS causes the OnReadFile callback is called.



Topic viewed 741 times

Number of guests: 1, registered members: 0, in total hidden: 0


Back to top

As of July 15, 2016 EldoS business operates as a division of /n software, inc. For more information, please read the announcement.

Got it!