From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4866D37187C; Thu, 15 Oct 2026 18:35:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792089353; cv=none; b=pDcvCOFyicVAMG0CMUrReQbc//stF0EYvwkem6TYeDh6cgluudCvHZPoVdYYmTgx9B5hgD/FAsiO/UR1R4oRmgRL0Owj2UbQ5zk7OaClhy/6gMSEexVp3kB9pHM5x827o6UYTNgonCBzMdgYTkXL1U07DtXpMrWvGaycH0tN/6c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792089353; c=relaxed/simple; bh=PgilridrbsX1FD+B++dHlE/QkecVuvuNNOJkor0MveQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=hh9gZhfc6WAP1gd0cTA9MA2bX82FbzPkm+pfTR2uNCnUndybNnXvIEbp5OqsSTZqWjKvynZNSS+WxIbuqHtouDm/2UPgWjKuPN07PfyoGj9if+KXW2480GM0DoWfyQdzLGqAWglBcQ9N5KSdekxeRg2a2Tz1KE3uM2ppZy4Mz+E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=or9vv7b0; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="or9vv7b0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6312E1F000C4; Thu, 15 Oct 2026 18:35:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792089349; bh=7ALLbBDzqNrieL0NuGOfMVmoGTKaJAvR3J1DurpebBs=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=or9vv7b01AP5M0f/NeP+B1iQj1ONyjyFrORPWECbAY65nUWmesOVHOtG9uSnscUHw NqCo/dT3ooNiqYQlSTGFzbJq9Tx0L6rlfDLnchqqm+5vZjyZNp9fcrX2YV3vGgVnrm AkflbiKVdnUXl7BV71lfMIGrH1OWeJFiKHFgSoUoURajeE3/RnHv/G6koLjVFE4gJD lkTfWWwaqM4yL35/dppK34NlOQFnJggy2EP3zRE5gm6Pp6jOKiMTc+DnwE/EXNIICC 9P67nMoIsoZ78BGD0QGJS+0hAseL+G650SpwyH8lYqlwMzO+VoA0AW8Z6xe4EcLdEz RsFUQRRSJGv4g== Date: Thu, 15 Oct 2026 18:35:48 +0000 From: Eric Biggers To: Alex Markuze Cc: linux-fscrypt@vger.kernel.org, "Theodore Y. Ts'o" , Jaegeuk Kim , Ilya Dryomov , Xiubo Li , Viacheslav Dubeyko , ceph-devel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] fscrypt: allow filesystems to disable symlink target caching Message-ID: <20261015183548.GE2170687@google.com> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Oct 15, 2026 at 05:46:24PM +0000, Alex Markuze wrote: > fscrypt stores decrypted symlink targets in inode->i_link. The VFS can > use this field without calling the filesystem's ->get_link() callback. > The target can remain valid after the access policy changes. > > The CephFS subvolume quarantine series adds access checks to > ->get_link(). Quarantine can revoke access after a target is cached. The > VFS cache can bypass these checks. > > The no_symlink_cache option in fscrypt_operations gives filesystems > control of this cache. It applies during target creation, lookup and > getattr. With this option set, the helpers do not read or update > ->i_link. The filesystem callback can then revalidate access. > > Uncached targets use the existing delayed-free callback. Each uncached > lookup allocates a temporary buffer and decrypts or encodes the target. > This lets Ceph reuse fscrypt's target validation and buffer ownership. > > The default setting keeps the current cache behavior for other > filesystems. Ceph selects the option so cached targets cannot bypass its > ->get_link() checks. > > Signed-off-by: Alex Markuze This sounds like a bug fix? If so, which commit is it fixing? - Eric