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Date: Tue, 3 Mar 2026 20:28:45 +0100
From: Lukas Wunner <lukas@wunner.de>
To: "Ionut Nechita (Wind River)" <ionut.nechita@windriver.com>
Cc: linux-pci@vger.kernel.org, helgaas@kernel.org, sebott@linux.ibm.com,
	schnelle@linux.ibm.com, bblock@linux.ibm.com, alifm@linux.ibm.com,
	julianr@linux.ibm.com, dtatulea@nvidia.com, mani@kernel.org,
	ionut_n2001@yahoo.com, sunlightlinux@gmail.com,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 1/1] PCI/IOV: Add reentrant locking in
 sriov_add_vfs/sriov_del_vfs for complete serialization
Message-ID: <aac2bUCCX3dZcwo0@wunner.de>
References: <20260303080903.28693-1-ionut.nechita@windriver.com>
 <20260303080903.28693-2-ionut.nechita@windriver.com>
 <aacmM9bAPstfDpgY@wunner.de>
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In-Reply-To: <aacmM9bAPstfDpgY@wunner.de>

On Tue, Mar 03, 2026 at 07:19:31PM +0100, Lukas Wunner wrote:
> Also, I would put this in the existing pci_lock_rescan_remove(),
> i.e. without introducing a new _reentrant variant, because these
> deadlocks exist elsewhere.  They're known to happen on unplug in
> pciehp as well.

Actually, scratch this particular comment.  The deadlock in pciehp
is actually an AB-BA deadlock, not recursive acquisition.