From owner-freebsd-current  Mon Sep  9 16: 5:28 2002
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Date: Mon, 9 Sep 2002 16:05:16 -0700 (PDT)
From: Don Lewis <dl-freebsd@catspoiler.org>
Subject: Re: vnode lock assertion problem in nfs_link()
To: current@FreeBSD.ORG, jeff@FreeBSD.ORG
Cc: current@FreeBSD.ORG, jeff@FreeBSD.ORG
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On  9 Sep, Don Lewis wrote:
> nfs_link() contains the following code:
> 
>         /*
>          * Push all writes to the server, so that the attribute cache
>          * doesn't get "out of sync" with the server.
>          * XXX There should be a better way!
>          */
>         VOP_FSYNC(vp, cnp->cn_cred, MNT_WAIT, cnp->cn_thread);
> 
> The problem is that vp is not locked by the caller, but VOP_FSYNC()
> expects its argument to be locked.
> 
> I think we can probably just lock and unlock vp around the call to
> VOP_FSYNC() ... 

Hmn, I think I just figured out this bit of code in ufs_link():

        if (tdvp != vp && (error = vn_lock(vp, LK_EXCLUSIVE, td))) {
                goto out2;
        }

It would probably be a bad thing to unconditionally lock vp if vp and
tdvp are the same ...


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