Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Wed, 22 Jul 2020 12:27:38 +0100
From:   Matthew Wilcox <willy@infradead.org>
To:     qiang.zhang@windriver.com
Cc:     akpm@linux-foundation.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm/dmapool.c: add lock protect in dma_pool_destroy
Message-ID: <20200722112738.GN15516@casper.infradead.org>
References: <20200722090516.28829-1-qiang.zhang@windriver.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20200722090516.28829-1-qiang.zhang@windriver.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Wed, Jul 22, 2020 at 05:05:16PM +0800, qiang.zhang@windriver.com wrote:
> When traversing "pool->page" linked list, to prevent possible
> other path operations this list, causing it to be destroyed, we
> should add lock protect for this list in dma_pool_destroy func.

The pool is being destroyed.  If somebody else is trying to allocate from
it while it's in the middle of being destroyed, there is a larger problem
to solve, and it can't be solved in the dmapool code.