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Date: Wed, 10 Jan 2024 22:07:34 +0300
From: Dan Carpenter <dan.carpenter@linaro.org>
To: David Howells <dhowells@redhat.com>
Cc: Jeff Layton <jlayton@kernel.org>, linux-cachefs@redhat.com,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] netfs, fscache: Prevent Oops in fscache_put_cache()
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 <1788108.1704913300@warthog.procyon.org.uk>
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On Wed, Jan 10, 2024 at 07:01:40PM +0000, David Howells wrote:
> Dan Carpenter <dan.carpenter@linaro.org> wrote:
> 
> >  	zero = __refcount_dec_and_test(&cache->ref, &ref);
> > -	trace_fscache_cache(debug_id, ref - 1, where);
> > +	trace_fscache_cache(cache->debug_id, ref - 1, where);
> 
> You can't do that if !zero.  cache may be deallocated between the two lines.

Ah...  Right.  I misread what was going on in the latter part of the
function.  Sorry, I'll resend.

regards,
dan carpenter