when i pend MJ_WRITE in my fs filter,system panic

During my copying file “A” in dir “DirA” to dir “DirB”,I pend the MJ_WRITE
irp ,queued in
my own list.But the MJ_READ irps are still going along. after a short time,
all the system
is down. the reason i think, is that the system buffer is crammed with the
file “A”'s buffer,
the OS can not even process the system files.

Any suggestions would be appreciated.

Best Regards.
Ming