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Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l4wEP-0007Ox-E9; Thu, 28 Jan 2021 01:36:21 +0000 Received: from szxga01-in.huawei.com ([45.249.212.187]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l4wEN-0007OC-0F for linux-nvme@lists.infradead.org; Thu, 28 Jan 2021 01:36:19 +0000 Received: from DGGEMM406-HUB.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4DR31n2S46zY3jw; Thu, 28 Jan 2021 09:35:09 +0800 (CST) Received: from dggema772-chm.china.huawei.com (10.1.198.214) by DGGEMM406-HUB.china.huawei.com (10.3.20.214) with Microsoft SMTP Server (TLS) id 14.3.498.0; Thu, 28 Jan 2021 09:36:14 +0800 Received: from [10.169.42.93] (10.169.42.93) by dggema772-chm.china.huawei.com (10.1.198.214) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2106.2; Thu, 28 Jan 2021 09:36:14 +0800 Subject: Re: [PATCH v2] nvme-multipath: Early exit if no path is available To: Daniel Wagner , References: <20210127103033.15318-1-dwagner@suse.de> From: Chao Leng Message-ID: Date: Thu, 28 Jan 2021 09:36:14 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <20210127103033.15318-1-dwagner@suse.de> Content-Language: en-US X-Originating-IP: [10.169.42.93] X-ClientProxiedBy: dggeme704-chm.china.huawei.com (10.1.199.100) To dggema772-chm.china.huawei.com (10.1.198.214) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210127_203619_301440_E4C6B474 X-CRM114-Status: GOOD ( 17.84 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sagi Grimberg , linux-kernel@vger.kernel.org, Jens Axboe , Hannes Reinecke , Keith Busch , Christoph Hellwig Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On 2021/1/27 18:30, Daniel Wagner wrote: > nvme_round_robin_path() should test if the return ns pointer is > valid. nvme_next_ns() will return a NULL pointer if there is no path > left. > > Fixes: 75c10e732724 ("nvme-multipath: round-robin I/O policy") > Cc: Hannes Reinecke > Signed-off-by: Daniel Wagner > --- > v2: > - moved NULL test into the if conditional statement > - added Fixes tag > > drivers/nvme/host/multipath.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c > index 9ac762b28811..282b7a4ea9a9 100644 > --- a/drivers/nvme/host/multipath.c > +++ b/drivers/nvme/host/multipath.c > @@ -221,7 +221,7 @@ static struct nvme_ns *nvme_round_robin_path(struct nvme_ns_head *head, > } > > for (ns = nvme_next_ns(head, old); > - ns != old; > + ns && ns != old; nvme_round_robin_path just be called when !"old". nvme_next_ns should not return NULL when !"old". It seems unnecessary to add checking "ns". Is there a bug that "old" is not in "head" list? If yes, we should fix it. > ns = nvme_next_ns(head, ns)) { > if (nvme_path_is_disabled(ns)) > continue; > _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme