From: Luis Henriques <lhenriques@suse.de>
To: Eric Biggers <ebiggers@kernel.org>
Cc: Jeff Layton <jlayton@kernel.org>,
ceph-devel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-fscrypt@vger.kernel.org
Subject: Re: [RFC PATCH v6 20/20] ceph: add fscrypt ioctls
Date: Tue, 20 Apr 2021 10:34:04 +0100 [thread overview]
Message-ID: <87wnsxl2pf.fsf@suse.de> (raw)
In-Reply-To: <YH3f6YQ7cxWCVb+b@gmail.com> (Eric Biggers's message of "Mon, 19 Apr 2021 12:54:17 -0700")
Eric Biggers <ebiggers@kernel.org> writes:
> On Mon, Apr 19, 2021 at 08:19:59AM -0400, Jeff Layton wrote:
>> On Mon, 2021-04-19 at 11:09 +0100, Luis Henriques wrote:
>> > Hi Jeff!
>> >
>> > Jeff Layton <jlayton@kernel.org> writes:
>> > <...>
>> > > +
>> > > + case FS_IOC_ADD_ENCRYPTION_KEY:
>> > > + ret = vet_mds_for_fscrypt(file);
>> > > + if (ret)
>> > > + return ret;
>> > > + atomic_inc(&ci->i_shared_gen);
>> >
>> > After spending some (well... a lot, actually) time looking at the MDS code
>> > to try to figure out my bug, I'm back at this point in the kernel client
>> > code. I understand that this code is trying to invalidate the directory
>> > dentries here. However, I just found that the directory we get at this
>> > point is the filesystem root directory, and not the directory we're trying
>> > to unlock.
>> >
>> > So, I still don't fully understand the issue I'm seeing, but I believe the
>> > code above is assuming 'ci' is the inode being unlocked, which isn't
>> > correct.
>> >
>> > (Note: I haven't checked if there are other ioctls getting the FS root.)
>> >
>> > Cheers,
>>
>>
>> Oh, interesting. That was my assumption. I'll have to take a look more
>> closely at what effect that might have then.
>>
>
> FS_IOC_ADD_ENCRYPTION_KEY, FS_IOC_REMOVE_ENCRYPTION_KEY,
> FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS, and FS_IOC_GET_ENCRYPTION_KEY_STATUS can
> all be executed on any file or directory on the filesystem (but preferably on
> the root directory) because they are operations on the filesystem, not on any
> specific file or directory. They deal with encryption keys, which can protect
> any number of encrypted directories (even 0 or a large number) and/or even loose
> encrypted files that got moved into an unencrypted directory.
>
> Note that this is all described in the documentation
> (https://www.kernel.org/doc/html/latest/filesystems/fscrypt.html).
> If the documentation is unclear please suggest improvements to it.
>
> Also, there shouldn't be any need for FS_IOC_ADD_ENCRYPTION_KEY to invalidate
> dentries itself because that is the point of fscrypt_d_revalidate(); the
> invalidation happens on-demand later.
I think the documentation is very clear regarding these ioctls. I guess I
just need to go refresh my memory as I have read that document long time
ago. Thanks for reminding me to do that ;-)
Cheers,
--
Luis
next prev parent reply other threads:[~2021-04-20 9:32 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 [this message]
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
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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