On Thu, 6 Feb 1997 I wrote:
> We have discovered what appears to be a bug in the client implementation
> of NFS in Solaris 2.5. If it isn't a bug, it's a worrying incompatibility.
> It can affect versions of Exim that are being used to do local
> deliveries into NFS-mounted files.
<snip>
I have been silly. Exim used to proceed as follows:
open mailbox
create lock file
lock open mailbox with fcntl
I don't know why I did it this way; I think I had "open the file before
locking" stuck in my brain. Anyway, I have now changed it so that it
does
create lock file
open mailbox
lock open mailbox with fcntl
Thus it should no longer be possible for two different Exims to have
the mailbox open simultaneously, and the attribute cacheing problem
should be avoided.
I have looked at the code of Pine, and it seems to do things in this
order as well, so that should interlock safely too. I don't know about
the other MUAs.
I will put something in the Exim manual pointing out that lock files
should always be used when delivering over NFS if more than one host is
involved.
--
Philip Hazel University Computing Service,
ph10@??? New Museums Site, Cambridge CB2 3QG,
P.Hazel@??? England. Phone: +44 1223 334714
