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Subject: Re: [PATCH v3 3/8] nvme: add error handling support for add_disk()
To:     Luis Chamberlain <mcgrof@kernel.org>, axboe@kernel.dk,
        martin.petersen@oracle.com, jejb@linux.ibm.com, kbusch@kernel.org,
        sagi@grimberg.me, adrian.hunter@intel.com, beanhuo@micron.com,
        ulf.hansson@linaro.org, avri.altman@wdc.com, swboyd@chromium.org,
        agk@redhat.com, snitzer@redhat.com, josef@toxicpanda.com
Cc:     hch@infradead.org, bvanassche@acm.org, ming.lei@redhat.com,
        linux-scsi@vger.kernel.org, linux-nvme@lists.infradead.org,
        linux-mmc@vger.kernel.org, dm-devel@redhat.com,
        nbd@other.debian.org, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, Christoph Hellwig <hch@lst.de>
References: <20210830212538.148729-1-mcgrof@kernel.org>
 <20210830212538.148729-4-mcgrof@kernel.org>
From:   Hannes Reinecke <hare@suse.de>
Message-ID: <677ca876-b003-d3b5-9e2e-d50ebef82cce@suse.de>
Date:   Mon, 6 Sep 2021 08:16:35 +0200
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On 8/30/21 11:25 PM, Luis Chamberlain wrote:
> We never checked for errors on add_disk() as this function
> returned void. Now that this is fixed, use the shiny new
> error handling.
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
> ---
>   drivers/nvme/host/core.c | 9 ++++++++-
>   1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 8679a108f571..687d3be563a3 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -3763,7 +3763,9 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
>   
>   	nvme_get_ctrl(ctrl);
>   
> -	device_add_disk(ctrl->device, ns->disk, nvme_ns_id_attr_groups);
> +	if (device_add_disk(ctrl->device, ns->disk, nvme_ns_id_attr_groups))
> +		goto out_cleanup_ns_from_list;
> +
>   	if (!nvme_ns_head_multipath(ns->head))
>   		nvme_add_ns_cdev(ns);
>   
> @@ -3773,6 +3775,11 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
>   
>   	return;
>   
> + out_cleanup_ns_from_list:
> +	nvme_put_ctrl(ctrl);
> +	down_write(&ctrl->namespaces_rwsem);
> +	list_del_init(&ns->list);
> +	up_write(&ctrl->namespaces_rwsem);
>    out_unlink_ns:
>   	mutex_lock(&ctrl->subsys->lock);
>   	list_del_rcu(&ns->siblings);
> 
I would rather turn this around, and call 'nvme_put_ctrl()' after 
removing the namespace from the list. But it's probably more a style 
issue, come to think of it.

Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
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