Subject: Re: nullfs ihash locking?
To: Blair Sadewitz <email@example.com>
From: Bill Stouder-Studenmund <firstname.lastname@example.org>
Date: 06/01/2007 11:40:55
Content-Type: text/plain; charset=us-ascii
On Mon, May 21, 2007 at 11:17:51PM -0400, Blair Sadewitz wrote:
> Would nullfs be subject to the same problem outlined in PR 36331? I
Probably. I expect that the nullfs code was copied from the ffs/ufs code=20
way back when. And enhanced with locks in the same way.
> don't know much about the internals of genfs or how the layerfs stuff
> works, but I'm getting what appear to be deadlocks only when using
layerfs is like genfs but it's only for layered file systems. Back when I=
was adding the overlay fs, I noticed that nullfs and umapfs and overlayfs=
and dmfs (the fs I was working on) all had large blocks of code that were=
almost the same. So I created layerfs and made routines that all of them=20
Maintaining the hash table for vnodes was one thing that went into
layerfs. They all did almost the same thing. The only difference was a
little bit of work in node creation once we have a new node. Thus there's
a callback in the layerfs node cache code.
> If someone could clue me in, I'd appreciate it.
I hope the above helps.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.3 (NetBSD)
-----END PGP SIGNATURE-----