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	Mon, 23 Dec 2024 07:26:55 +0000
Date: Mon, 23 Dec 2024 07:26:55 +0000
From: Al Viro <viro@zeniv.linux.org.uk>
To: NeilBrown <neilb@suse.de>
Cc: Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 10/11] VFS: take a shared lock for create/remove
 directory operations.
Message-ID: <20241223072655.GM1977892@ZenIV>
References: <>
 <20241223051941.GK1977892@ZenIV>
 <173493787613.11072.4293875424077013617@noble.neil.brown.name>
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Sender: Al Viro <viro@ftp.linux.org.uk>

On Mon, Dec 23, 2024 at 06:11:16PM +1100, NeilBrown wrote:
> ... Yes, thanks.
> 
> So I need __d_unalias() to effectively do a "try_lock" of
> DCACHE_PAR_UPDATE and hold the lock across __d_move().
> I think that would address the concerned you raised.
> 
> Did you see anything else that might be problematic?

That might work with ->d_parent, but it won't help with ->d_name
in same-parent case of __d_unalias()...