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Tue, 01 Jul 2025 07:14:17 -0700 (PDT) From: Jens Axboe To: hch@lst.de, yukuai3@huawei.com, Yu Kuai Cc: penguin-kernel@I-love.SAKURA.ne.jp, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yi.zhang@huawei.com, yangerkun@huawei.com, johnny.chenyi@huawei.com In-Reply-To: <20250630112828.421219-1-yukuai1@huaweicloud.com> References: <20250630112828.421219-1-yukuai1@huaweicloud.com> Subject: Re: [PATCH v2] brd: fix sleeping function called from invalid context in brd_insert_page() Message-Id: <175137925672.318770.9783780559206172712.b4-ty@kernel.dk> Date: Tue, 01 Jul 2025 08:14:16 -0600 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Mailer: b4 0.14.3-dev-d7477 On Mon, 30 Jun 2025 19:28:28 +0800, Yu Kuai wrote: > __xa_cmpxchg() is called with rcu_read_lock(), and it will allocate > memory if necessary. > > Fix the problem by moving rcu_read_lock() after __xa_cmpxchg(), meanwhile, > it still should be held before xa_unlock(), prevent returned page to be > freed by concurrent discard. > > [...] Applied, thanks! [1/1] brd: fix sleeping function called from invalid context in brd_insert_page() commit: 0d519bb0de3bf0ac9e6f401d4910fc119062d7be Best regards, -- Jens Axboe