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
Subject: Re: [PATCH] fs: avoid calls to legitimize_links() if possible
Date: Mon, 10 Nov 2025 01:27:05 +0000 [thread overview]
Message-ID: <20251110012705.GI2441659@ZenIV> (raw)
In-Reply-To: <20251109185409.1330720-1-mjguzik@gmail.com>
On Sun, Nov 09, 2025 at 07:54:09PM +0100, Mateusz Guzik wrote:
> @@ -882,8 +887,10 @@ static bool try_to_unlazy(struct nameidata *nd)
>
> BUG_ON(!(nd->flags & LOOKUP_RCU));
>
> - if (unlikely(!legitimize_links(nd)))
> - goto out1;
> + if (unlikely(need_legitimize_links(nd))) {
> + if (unlikely(!legitimize_links(nd)))
> + goto out1;
> + }
> if (unlikely(!legitimize_path(nd, &nd->path, nd->seq)))
> goto out;
> if (unlikely(!legitimize_root(nd)))
> @@ -917,8 +924,10 @@ static bool try_to_unlazy_next(struct nameidata *nd, struct dentry *dentry)
> int res;
> BUG_ON(!(nd->flags & LOOKUP_RCU));
>
> - if (unlikely(!legitimize_links(nd)))
> - goto out2;
> + if (unlikely(need_legitimize_links(nd))) {
> + if (unlikely(!legitimize_links(nd)))
> + goto out2;
> + }
> res = __legitimize_mnt(nd->path.mnt, nd->m_seq);
> if (unlikely(res)) {
> if (res > 0)
Seeing that odds of extra callers showing up are pretty much nil,
I think your need_legitimize_links() is only obfuscating things.
Let's just make it
if (unlikely(nd->depth) && !legitimize_links(nd))
goto ...
and be done with that.
prev parent reply other threads:[~2025-11-10 1:27 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-09 18:54 [PATCH] fs: avoid calls to legitimize_links() if possible Mateusz Guzik
2025-11-10 1:27 ` Al Viro [this message]
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