Subject: Re: nullfs still doesn't reclaim space (PR#15555)
To: Jeremy C. Reed <>
From: Simon Burge <>
List: tech-kern
Date: 02/13/2003 09:32:16
"Jeremy C. Reed" wrote:

> I use mount_null with mount_mfs on live CDs (memory- and cd-based) for
> teaching classes and giving presentations.
> Almost a year ago, I received a patch from enami t. for netbsd-1.5 so
> nullfs would reclaim space. I think it was
> This worked
> great for my 1.5.* based CDs.
> I was guessing/hoping that 1.6 had this problem fixed.

No, and still a problem with -current too :-(

> Anyways, will someone look at enami's patch and PR #15555?
> You can see some discussion also in the March 2002 tech-kern mailing
> lists: "mount_mfs (with mount_null) won't reclaim space" and "CVS commit:
> syssrc/sys/miscfs/nullfs".

I think that thread shows that enami's proposed patch doesn't fix this
problem.  Someone needs to implement Bill's vnode upcall mechanism.

> Also, I don't know if related, but with 1.5.*, doing a tail(1) of a file
> under the mount_null/mount_mfs combination often wouldn't really show the
> end of a file. But it appears to work with 1.6.

I suspect that was separate lossage that UBC fixed (but I'm not really
sure - only that I noticed it fixed when I went to 1.6).

Simon Burge                            <>
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