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[91.12.100.221]) by smtp.gmail.com with ESMTPSA id z79sm1824154wmc.17.2021.09.22.04.24.38 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 22 Sep 2021 04:24:38 -0700 (PDT) Subject: Re: [PATCH] mm/swapfile: Remove needless request_queue NULL pointer check To: Xu Wang , akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20210917082111.33923-1-vulab@iscas.ac.cn> From: David Hildenbrand Organization: Red Hat Message-ID: <8327ab0b-a6f4-7580-fb79-b079500c26fe@redhat.com> Date: Wed, 22 Sep 2021 13:24:37 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210917082111.33923-1-vulab@iscas.ac.cn> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Stat-Signature: izzag9hdfmc38hpomtehrb14h715mr13 Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="A/7u5koL"; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf29.hostedemail.com: domain of david@redhat.com has no SPF policy when checking 216.205.24.124) smtp.mailfrom=david@redhat.com X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: B4DE59000264 X-HE-Tag: 1632309881-89676 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 17.09.21 10:21, Xu Wang wrote: > The request_queue pointer returned from bdev_get_queue() shall > never be NULL, so the null check is unnecessary, just remove it. > > Signed-off-by: Xu Wang > --- > mm/swapfile.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/swapfile.c b/mm/swapfile.c > index 22d10f713848..42027d213fd2 100644 > --- a/mm/swapfile.c > +++ b/mm/swapfile.c > @@ -3118,7 +3118,7 @@ static bool swap_discardable(struct swap_info_struct *si) > { > struct request_queue *q = bdev_get_queue(si->bdev); > > - if (!q || !blk_queue_discard(q)) > + if (!blk_queue_discard(q)) > return false; > > return true; > Right, there is even a comment in bdev_get_queue "this is never NULL". Acked-by: David Hildenbrand -- Thanks, David / dhildenb