linux-kernel - Re: [PATCH 3/5] fs, xfs: convert xlog_ticket.t_ref from atomic_t to refcount

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Message-ID: <20170308155059.GA4353@infradead.org>
Date:   Wed, 8 Mar 2017 07:50:59 -0800
From:   Christoph Hellwig <hch@...radead.org>
To:     Elena Reshetova <elena.reshetova@...el.com>
Cc:     darrick.wong@...cle.com, linux-kernel@...r.kernel.org,
        linux-xfs@...r.kernel.org, Hans Liljestrand <ishkamiel@...il.com>,
        Kees Cook <keescook@...omium.org>,
        David Windsor <dwindsor@...il.com>
Subject: Re: [PATCH 3/5] fs, xfs: convert xlog_ticket.t_ref from atomic_t to
 refcount_t

> -	ASSERT(atomic_read(&ticket->t_ref) > 0);
> -	atomic_inc(&ticket->t_ref);
> +	ASSERT(refcount_read(&ticket->t_ref) > 0);
> +	refcount_inc(&ticket->t_ref);

With strict refcount semantics refcount_inc should check that
the count is larger than 0, otherwise we'd need to use 
recount_inc_not_zero or whatever you're going to call it.

Is that something the recount code does / could do?