From: Luis Henriques <lhenriques@suse.de>
To: Jeff Layton <jlayton@kernel.org>
Cc: ceph-devel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-fscrypt@vger.kernel.org
Subject: Re: [RFC PATCH v6 00/20] ceph+fscrypt: context, filename and symlink support
Date: Mon, 19 Apr 2021 17:03:26 +0100 [thread overview]
Message-ID: <871rb6mfch.fsf@suse.de> (raw)
In-Reply-To: <e411e914cd2d329e4b0e335968c21ba85f6e89c7.camel@kernel.org> (Jeff Layton's message of "Mon, 19 Apr 2021 08:23:18 -0400")
Jeff Layton <jlayton@kernel.org> writes:
> On Mon, 2021-04-19 at 11:30 +0100, Luis Henriques wrote:
...
> Ouch. That looks like a real bug, alright.
>
> Basically when building the path, we occasionally need to fetch the
> crypto context for parent inodes and such, and that can cause us to
> recurse back into __ceph_getxattr and try to issue another RPC to the
> MDS.
>
> I'll have to look and see what we can do. Maybe it's safe to drop the
> mdsc->mutex while we're building the path? Or maybe this is a good time
> to re-think a lot of the really onerous locking in this codepath?
>
> I'm open to suggestions here...
Yeah, I couldn't see a good fix at a first glace. Dropping the mutex
while building the path was my initial thought too but it's not easy to
proof that's a safe thing to do.
The other idea I had was to fetch all the needed fscrypt contexts at the
end, after building the path. But I didn't found a way for doing that
because to build the path... we need the contexts.
It looks like this leaves us with the locking rethinking option.
/me tries harder to find another way out
Cheers,
--
Luis
next prev parent reply other threads:[~2021-04-19 16:02 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-13 17:50 [RFC PATCH v6 00/20] ceph+fscrypt: context, filename and symlink support Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 01/20] vfs: export new_inode_pseudo Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 02/20] fscrypt: export fscrypt_base64_encode and fscrypt_base64_decode Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 03/20] fscrypt: export fscrypt_fname_encrypt and fscrypt_fname_encrypted_size Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 04/20] fscrypt: add fscrypt_context_for_new_inode Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 05/20] ceph: crypto context handling for ceph Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 06/20] ceph: implement -o test_dummy_encryption mount option Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 07/20] ceph: preallocate inode for ops that may create one Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 08/20] ceph: add routine to create fscrypt context prior to RPC Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 09/20] ceph: make ceph_msdc_build_path use ref-walk Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 10/20] ceph: add encrypted fname handling to ceph_mdsc_build_path Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 11/20] ceph: decode alternate_name in lease info Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 12/20] ceph: send altname in MClientRequest Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 13/20] ceph: properly set DCACHE_NOKEY_NAME flag in lookup Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 14/20] ceph: make d_revalidate call fscrypt revalidator for encrypted dentries Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 15/20] ceph: add helpers for converting names for userland presentation Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 16/20] ceph: add fscrypt support to ceph_fill_trace Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 17/20] ceph: add support to readdir for encrypted filenames Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 18/20] ceph: create symlinks with encrypted and base64-encoded targets Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 19/20] ceph: make ceph_get_name decrypt filenames Jeff Layton
2021-04-13 17:50 ` [RFC PATCH v6 20/20] ceph: add fscrypt ioctls Jeff Layton
2021-04-19 10:09 ` Luis Henriques
2021-04-19 12:19 ` Jeff Layton
2021-04-19 19:54 ` Eric Biggers
2021-04-20 9:34 ` Luis Henriques
2021-04-20 11:45 ` Jeff Layton
2021-04-19 10:30 ` [RFC PATCH v6 00/20] ceph+fscrypt: context, filename and symlink support Luis Henriques
2021-04-19 12:23 ` Jeff Layton
2021-04-19 16:03 ` Luis Henriques [this message]
2021-04-19 16:28 ` Jeff Layton
2021-04-20 10:11 ` Luis Henriques
2021-04-20 15:52 ` Jeff Layton
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