Received-SPF: pass (google.com: domain of linux-kernel+bounces-208771-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99;
Message-ID: <e8fa4c36-49e5-40b8-9cea-6b3b61aa3240@grimberg.me>
Date: Mon, 10 Jun 2024 22:05:00 +0300
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: Kernel OOPS while creating a NVMe Namespace
To: Keith Busch <kbusch@kernel.org>,
 Venkat Rao Bagalkote <venkat88@linux.vnet.ibm.com>
Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
 linux-nvme@lists.infradead.org, sachinp@linux.vnet.com
References: <2312e6c3-a069-4388-a863-df7e261b9d70@linux.vnet.ibm.com>
 <ZmdLlaVO-QUug5aj@kbusch-mbp.dhcp.thefacebook.com>
Content-Language: en-US
From: Sagi Grimberg <sagi@grimberg.me>
In-Reply-To: <ZmdLlaVO-QUug5aj@kbusch-mbp.dhcp.thefacebook.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit


On 10/06/2024 21:53, Keith Busch wrote:
> On Mon, Jun 10, 2024 at 01:21:00PM +0530, Venkat Rao Bagalkote wrote:
>> Issue is introduced by the patch: be647e2c76b27f409cdd520f66c95be888b553a3.
> My mistake. The namespace remove list appears to be getting corrupted
> because I'm using the wrong APIs to replace a "list_move_tail". This is
> fixing the issue on my end:
>
> ---
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 7c9f91314d366..c667290de5133 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -3959,9 +3959,10 @@ static void nvme_remove_invalid_namespaces(struct nvme_ctrl *ctrl,
>   
>   	mutex_lock(&ctrl->namespaces_lock);
>   	list_for_each_entry_safe(ns, next, &ctrl->namespaces, list) {
> -		if (ns->head->ns_id > nsid)
> -			list_splice_init_rcu(&ns->list, &rm_list,
> -					     synchronize_rcu);
> +		if (ns->head->ns_id > nsid) {
> +			list_del_rcu(&ns->list);
> +			list_add_tail_rcu(&ns->list, &rm_list);
> +		}
>   	}
>   	mutex_unlock(&ctrl->namespaces_lock);
>   	synchronize_srcu(&ctrl->srcu);
> --

Can we add a reproducer for this in blktests? I'm assuming that we can 
easily trigger this
with adding/removing nvmet namespaces?