Subject: NFSv3 O_EXCL
To: None <>
From: None <>
List: tech-kern
Date: 07/27/2000 11:19:22
>> The problem with the change you suggest is that a lot of programs don't
>> expect open()s with O_EXCL to always fail (which is what will happen
>> after the change you suggest for servers that don't support the option).
>It seems to me that it's a lot better than the alternative, having the open
>"succeed" but not be exclusive!  After all, you don't ask for O_EXCL if you
>don't care whether the operation's exclusive or not.

I suppose that's reasonable, so long as the man page makes it clear that
this can happen (maybe a message syslog'd when it happens?) and then the
mount can't be used for O_EXCL. (Maybe it should be a mount option of
"return error" vs "silently ignore it". Sometimes a mount option is a
good thing, even if its main purpose is to document the problem. That's
why Mike Karels and I made "use a reserved port" a mount option in the
old days. We wanted to document the fact that it has no effect upon
security in most cases, contrary to popular folklore at the time.)

Anyhow, have fun with whichever you choose, rick