years ago, I tried to avoid the extra RPC of doing an Open
after a Lookup, by combining them in the same compound RPC.
It turned out this did not work for multiple open owners, so it was
only enabled for "oneopenown".
(Since few use this mount option, I have not seen issues with it
reported by others and it worked ok for my testing.)

However, I now realize that Open works because a vnode lock
on the vnode being opened guarantees that the Open does not
go away during the VOP_OPEN().
Unfortunately, for VOP_LOOKUP(), it is the directory that is vnode
locked and a vnode lock on the file being looked up is not acquired
until the Lookup reply is processed.
--> To fix this, I think I need to delay the open processing until after
      the vnode lock on the file has been acquired
or
--> Just back this Open in Lookup patch out, since it can only be
     made to work for "oneopenown" and it only reduces each Open
     by one RPC.

The trivial patch I posted just disables the Open in Lookup RPC
optimization, so it should have the same effect as backing the patch
(it is actually several git commits) out.

The good news is that it looks like I finally know why you were
having problems others were not reporting. (I have no idea why 14.1
is crashing when previous versions would hang, etc, but crashes are
much easier to diagnose.)

rick

>
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> John Carr
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