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From: Al Viro <viro@zeniv.linux.org.uk>
To: Mateusz Guzik <mjguzik@gmail.com>
Cc: brauner@kernel.org, jack@suse.cz, linux-kernel@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, clm@meta.com
Subject: Re: [PATCH v2] fs: make sure to fail try_to_unlazy() and try_to_unlazy() for LOOKUP_CACHED
Date: Wed, 17 Dec 2025 09:08:33 +0000	[thread overview]
Message-ID: <20251217090833.GS1712166@ZenIV> (raw)
In-Reply-To: <20251217084704.2323682-1-mjguzik@gmail.com>

On Wed, Dec 17, 2025 at 09:47:04AM +0100, Mateusz Guzik wrote:
> Otherwise the slowpath can be taken by the caller, defeating the flag.
> 
> This regressed after calls to legitimize_links() started being
> conditionally elided and stems from the routine always failing
> after seeing the flag, regardless if there were any links.
> 
> In order to address both the bug and the weird semantics make it illegal
> to call legitimize_links() with LOOKUP_CACHED and handle the problem at
> the two callsites.
> 
> Pull up ->depth = 0 to drop_links() to avoid repeating it in the
> callers.
> 
> One remaining weirdness is terminate_walk() walking the symlink stack
> after drop_links().

What weirdness?  If we are not in RCU mode, we need to drop symlink bodies
*and* drop symlink references?

  reply	other threads:[~2025-12-17  9:07 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-12-17  8:47 [PATCH v2] fs: make sure to fail try_to_unlazy() and try_to_unlazy() for LOOKUP_CACHED Mateusz Guzik
2025-12-17  9:08 ` Al Viro [this message]
2025-12-17  9:11   ` Mateusz Guzik
2025-12-17 10:06     ` Al Viro
2025-12-17 10:13       ` Mateusz Guzik
2025-12-17 10:27         ` Mateusz Guzik
2025-12-17 10:48         ` Al Viro

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