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From: Jason Gunthorpe <jgg@ziepe.ca>
To: Shifeng Li <lishifeng@sangfor.com.cn>
Cc: leon@kernel.org, wenglianfa@huawei.com, gustavoars@kernel.org,
	linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org,
	Shifeng Li <lishifeng1992@126.com>,
	"Ding, Hui" <dinghui@sangfor.com.cn>
Subject: Re: [PATCH] RDMA/device: Fix a race between mad_client and cm_client init
Date: Thu, 4 Jan 2024 08:37:28 -0400	[thread overview]
Message-ID: <20240104123728.GC50608@ziepe.ca> (raw)
In-Reply-To: <80cac9fd-7fed-403e-8889-78e2fc7a49b0@sangfor.com.cn>

On Thu, Jan 04, 2024 at 02:48:14PM +0800, Shifeng Li wrote:

> The root cause is that mad_client and cm_client may init concurrently
> when devices_rwsem write semaphore is downgraded in enable_device_and_get() like:

That can't be true, the module loader infrastructue ensures those two
things are sequential.

You are trying to say that the post-client fixup stuff will still see
the DEVICE_REGISTERED before it reaches the clients_rwsem lock?

That probably just says the clients_rwsem should be obtained before
changing the DEVICE_STATE too :\

Jason

  parent reply	other threads:[~2024-01-04 12:37 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-01-02  3:43 [PATCH] RDMA/device: Fix a race between mad_client and cm_client init Shifeng Li
2024-01-02  8:58 ` Leon Romanovsky
2024-01-02 11:33   ` Shifeng Li
2024-01-02 11:58     ` Leon Romanovsky
2024-01-02 12:30       ` Shifeng Li
2024-01-03 18:48 ` Jason Gunthorpe
     [not found]   ` <80cac9fd-7fed-403e-8889-78e2fc7a49b0@sangfor.com.cn>
2024-01-04 12:37     ` Jason Gunthorpe [this message]
2024-01-05  8:15       ` Shifeng Li
2024-01-05 14:19         ` Jason Gunthorpe
2024-01-15  3:27           ` Shifeng Li
2024-01-06  2:12       ` Ding Hui
2024-01-15 13:47         ` Jason Gunthorpe
     [not found]           ` <354e2bf7-a8b4-629d-3d2d-35951a52e8bd@sangfor.com.cn>
2024-01-26  2:25             ` Shifeng Li
2024-02-01  0:04               ` Jason Gunthorpe

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