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Date: Fri, 5 Apr 2024 08:51:35 +0200
From: Christoph Hellwig <hch@lst.de>
To: Amir Goldstein <amir73il@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
	syzbot <syzbot+9a5b0ced8b1bfb238b56@syzkaller.appspotmail.com>,
	gregkh@linuxfoundation.org, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com,
	tj@kernel.org, valesini@yandex-team.ru,
	Christoph Hellwig <hch@lst.de>,
	Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
	Miklos Szeredi <miklos@szeredi.hu>
Subject: Re: [syzbot] [kernfs?] possible deadlock in kernfs_fop_llseek
Message-ID: <20240405065135.GA3959@lst.de>
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On Thu, Apr 04, 2024 at 12:33:40PM +0300, Amir Goldstein wrote:
> I don't follow what you are saying.
> Which code is in non-starter violation?
> kernfs for calling lookup_bdev() with internal of->mutex held?

That is a huge problem, and has been causing endless annoying lockdep
chains in the block layer for us.  If we have some way to kill this
the whole block layer would benefit.