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From: Arnd Bergmann <arnd@arndb.de>
To: "J. Bruce Fields" <bfields@fieldses.org>
Subject: Re: [PATCH] Remove BKL from fs/locks.c
Date: Thu, 16 Sep 2010 10:28:56 +0200
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On Wednesday 15 September 2010 22:42:03 J. Bruce Fields wrote:
> Looking over the server code....  The only code I see under the BKL is:
> 
>         - a few lease callbacks in fs/nfsd/nfs4state.c, none of which
>           sleep at this point, so all should be fine under a spinlock or
>           whatever we want.
>         - fs/nfsd/nfs4state.c:check_for_locks(), which explicitly takes
>           the BKL itself.  All it does, though, is walk the lock list
>           for a given file and check whether any of them have a given
>           owner.  It would be trivial to put it under some other lock
>           and/or move it to locks.c.

Ok. In the version of the patch I sent out yesterday, I came to the
same conclusion and put both of these under lock_flocks(), which
is still the BKL but can be converted to a spinlock after we have
sorted out ceph and lockd. If you and others are fine with this patch,
I'll add it to my bkl/config series.

Note that walking the i_flock list needs to use lock_flocks()
(or the BKL), not a private lock. I guess that's what you are saying
anyway, just making sure.

	Arnd