From: Greg KH <gregkh@linuxfoundation.org>
To: zhoumin <teczm@foxmail.com>
Cc: rafael@kernel.org, dakr@kernel.org, akpm@linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH] kobject: fix uevent helper execution order issues
Date: Tue, 19 Aug 2025 20:29:12 +0200 [thread overview]
Message-ID: <2025081956-untie-elude-7880@gregkh> (raw)
In-Reply-To: <tencent_22B2504A61A3281D6A2590CB43ABCCEC790A@qq.com>
On Wed, Aug 20, 2025 at 01:18:28AM +0800, zhoumin wrote:
> The current use of the UMH_NO_WAIT parameter does not guarantee the
> sequential execution of CONFIG_STATIC_USERMODEHELPER_PATH.
There is never any such guarantee. Unless you are on a single processor
system.
> For example, when fdisk completes and issues a BLKRRPART ioctl command,
> kernel first sending remove events followed by an add events. However,
> process CONFIG_STATIC_USERMODEHELPER_PATH may execute
> out-of-order—potentially handling the add before the remove. This can
> result in the new partition being unexpectedly unmounted instead of mounted
> as intended.
Why are you not looking at the SEQNUM value? That should be what orders
the events, right? Otherwise how would any of this work? :)
Also, what usermode helper program are you using that requires a binary?
What is wrong with udev?
thanks,
greg k-h
next prev parent reply other threads:[~2025-08-19 18:29 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-19 17:18 [RFC PATCH] kobject: fix uevent helper execution order issues zhoumin
2025-08-19 18:29 ` Greg KH [this message]
2025-08-20 14:04 ` zhoumin
2025-08-20 14:23 ` Greg KH
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