Fix up locking problems in fifo_open() and fifo_close():

	Sleep on the vnode interlock while waiting for another
	caller to increment fi_readers or fi_writers.  Hold the
	vnode interlock while incrementing fi_readers or fi_writers
	to prevent a wakeup from being missed.

	Only access fi_readers and fi_writers while holding the vnode
	lock.  Previously fifo_close() decremented their values without
	holding a lock.

	Move resource deallocation from fifo_close() to fifo_inactive(),
	which allows the VOP_CLOSE() call in the error return path in
	fifo_open() to be removed.  Fifo_open() was calling VOP_CLOSE()
	with the vnode lock held, in violation the current vnode locking
	API.  Also the way fifo_close() used vrefcnt() to decide whether
	to deallocate resources was bogus according to comments in the
	vrefcnt() implementation.

Reviewed by:	bde

0 files changed, 0 insertions, 0 deletions