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From: Chao Leng <lengchao@huawei.com>
To: Daniel Wagner <dwagner@suse.de>, <linux-nvme@lists.infradead.org>
Cc: Sagi Grimberg <sagi@grimberg.me>, <linux-kernel@vger.kernel.org>,
	"Jens Axboe" <axboe@fb.com>, Hannes Reinecke <hare@suse.de>,
	Keith Busch <kbusch@kernel.org>, Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH v2] nvme-multipath: Early exit if no path is available
Date: Thu, 28 Jan 2021 09:36:14 +0800	[thread overview]
Message-ID: <ca8be10a-11fb-dd4d-3606-f9e75a42c99d@huawei.com> (raw)
In-Reply-To: <20210127103033.15318-1-dwagner@suse.de>



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 <hare@suse.de>
> Signed-off-by: Daniel Wagner <dwagner@suse.de>
> ---
> 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;
> 

WARNING: multiple messages have this Message-ID (diff)
From: Chao Leng <lengchao@huawei.com>
To: Daniel Wagner <dwagner@suse.de>, <linux-nvme@lists.infradead.org>
Cc: Sagi Grimberg <sagi@grimberg.me>,
	linux-kernel@vger.kernel.org, Jens Axboe <axboe@fb.com>,
	Hannes Reinecke <hare@suse.de>, Keith Busch <kbusch@kernel.org>,
	Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH v2] nvme-multipath: Early exit if no path is available
Date: Thu, 28 Jan 2021 09:36:14 +0800	[thread overview]
Message-ID: <ca8be10a-11fb-dd4d-3606-f9e75a42c99d@huawei.com> (raw)
In-Reply-To: <20210127103033.15318-1-dwagner@suse.de>



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 <hare@suse.de>
> Signed-off-by: Daniel Wagner <dwagner@suse.de>
> ---
> 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;
> 

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  parent reply	other threads:[~2021-01-28  1:37 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-27 10:30 [PATCH v2] nvme-multipath: Early exit if no path is available Daniel Wagner
2021-01-27 10:30 ` Daniel Wagner
2021-01-27 10:34 ` Hannes Reinecke
2021-01-27 10:34   ` Hannes Reinecke
2021-01-27 16:49 ` Christoph Hellwig
2021-01-27 16:49   ` Christoph Hellwig
2021-01-28  1:31 ` Chao Leng
2021-01-28  1:31   ` Chao Leng
2021-01-28  7:58   ` Daniel Wagner
2021-01-28  7:58     ` Daniel Wagner
2021-01-28  9:18     ` Chao Leng
2021-01-28  9:18       ` Chao Leng
2021-01-28  9:23       ` Hannes Reinecke
2021-01-28  9:23         ` Hannes Reinecke
2021-01-29  1:18         ` Chao Leng
2021-01-29  1:18           ` Chao Leng
2021-01-28  9:40       ` Daniel Wagner
2021-01-28  9:40         ` Daniel Wagner
2021-01-29  1:23         ` Chao Leng
2021-01-29  1:23           ` Chao Leng
2021-01-29  1:42           ` Sagi Grimberg
2021-01-29  1:42             ` Sagi Grimberg
2021-01-29  3:07             ` Chao Leng
2021-01-29  3:07               ` Chao Leng
2021-01-29  3:30               ` Sagi Grimberg
2021-01-29  3:30                 ` Sagi Grimberg
2021-01-29  3:36                 ` Chao Leng
2021-01-29  3:36                   ` Chao Leng
2021-01-29  7:06               ` Hannes Reinecke
2021-01-29  7:06                 ` Hannes Reinecke
2021-01-29  7:45                 ` Chao Leng
2021-01-29  8:33                   ` Hannes Reinecke
2021-01-29  8:46                     ` Chao Leng
2021-01-29  9:20                       ` Hannes Reinecke
2021-02-01  2:16                         ` Chao Leng
2021-02-01  2:16                           ` Chao Leng
2021-02-01  7:29                           ` Hannes Reinecke
2021-02-01  7:29                             ` Hannes Reinecke
2021-02-01  8:47                             ` Chao Leng
2021-02-01  8:47                               ` Chao Leng
2021-02-01  8:57                               ` Hannes Reinecke
2021-02-01  8:57                                 ` Hannes Reinecke
2021-02-01  9:40                                 ` Chao Leng
2021-02-01  9:40                                   ` Chao Leng
2021-02-01 10:45                                   ` Hannes Reinecke
2021-02-01 10:45                                     ` Hannes Reinecke
2021-02-02  1:12                                     ` Chao Leng
2021-02-02  1:12                                       ` Chao Leng
2021-01-28  1:36 ` Chao Leng [this message]
2021-01-28  1:36   ` Chao Leng

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