file io in port-driver

Dear All!
I know this is not Win95 discussion group, but i really need help :frowning:
I’m writing Win95 port-driver that must perfom file io during IOP
processing. I’ve been told about deadlocks if IOPs that need file io are
processed syncronously so i’ve made io thread (via
_VWIN32_Create_Ring0Thread) that waits until IOP arrives and than processes
first IOP in queue (processing includes file io)

The problem is: i got deadlock at the first attempt to read from file after
VRP for the newly mounted volume is created. (a few IOPs arrived before VRP
is created are handled properly)

I use IFSMgr_Ring0_FileIO to perfom fileio operations and
standart VMM list services to organize IOP queue.
Procedure i insert into calldown list does just the following:
enqueus IOP (and signals semaphore indicating a new IOP arrived) if it is
asyncronous (~IORF_ASYNC_COMMAND) and immediatly processes it if it is
syncronous. Deadlock occurs in the async IOP.

Do you have any ideas about what is happening?
Maybe you know where to get sample driver that perfom file io on IOP

Thanks for any help!


p.s. do you know any Win95 device drivers discussion group?