Date: Fri, 2 Mar 2012 00:33:51 +0100 From: Peter Holm <peter@holm.cc> To: John Baldwin <jhb@freebsd.org> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r226967 - head/sys/ufs/ufs Message-ID: <20120301233351.GA24773@x2.osted.lan> In-Reply-To: <201203011647.41313.jhb@freebsd.org> References: <201110311501.p9VF1lrf020688@svn.freebsd.org> <201203011647.41313.jhb@freebsd.org>
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On Thu, Mar 01, 2012 at 04:47:41PM -0500, John Baldwin wrote: > On Monday, October 31, 2011 11:01:47 am Peter Holm wrote: > > Author: pho > > Date: Mon Oct 31 15:01:47 2011 > > New Revision: 226967 > > URL: http://svn.freebsd.org/changeset/base/226967 > > > > Log: > > The kern_renameat() looks up the fvp using the DELETE flag, which causes > > the removal of the name cache entry for fvp. > > > > Reported by: Anton Yuzhaninov <citrin citrin ru> > > In collaboration with: kib > > MFC after: 1 week > > > > Modified: > > head/sys/ufs/ufs/ufs_vnops.c > > So I ran into this at work recently, and even this fix applied I was still > seeing rename()'s that were seemingly not taking effect. After getting some > extra KTR traces, I figured out that the same purge needs to be applied to the > destination vnode. Specifically, the issue I ran into was that was renaming > 'foo' to 'bar', but lookups for 'bar' were still returning the old file. The > reason was that a lookup after the namei(RENAME) of the destination while > ufs_rename() had its locks dropped was readding the name cache entry for > 'bar', and then a cache_lookup() of 'bar' would return the old vnode as long > as that vnode was valid (e.g. if it had a link in another location, or other > processes had an open file descriptor for it). I'm currently testing the > patch below: > You wouldn't happen to have a small test scenario that demonstrates this? I'm not able to reproduce the problem, based on your description. I'll try some more tomorrow. - Peter
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