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From:   =?utf-8?Q?Lu=C3=ADs_Henriques?= <lhenriques@suse.de>
To:     Jeff Layton <jlayton@kernel.org>
Cc:     Xiubo Li <xiubli@redhat.com>, Ilya Dryomov <idryomov@gmail.com>,
        ceph-devel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/3] ceph: add support for encrypted snapshot names
References: <20220304161403.19295-1-lhenriques@suse.de>
        <20220304161403.19295-4-lhenriques@suse.de>
        <c3d26fbd7691155cedc06dd44344d868f4d9112a.camel@kernel.org>
Date:   Sat, 05 Mar 2022 14:34:52 +0000
In-Reply-To: <c3d26fbd7691155cedc06dd44344d868f4d9112a.camel@kernel.org> (Jeff
        Layton's message of "Fri, 04 Mar 2022 13:25:44 -0500")
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Jeff Layton <jlayton@kernel.org> writes:

> On Fri, 2022-03-04 at 16:14 +0000, Lu=C3=ADs Henriques wrote:
>> Since filenames in encrypted directories are already encrypted and shown
>> as a base64-encoded string when the directory is locked, snapshot names
>> should show a similar behaviour.
>>=20
>> Signed-off-by: Lu=C3=ADs Henriques <lhenriques@suse.de>
>> ---
>>  fs/ceph/dir.c   |  9 +++++++++
>>  fs/ceph/inode.c | 13 +++++++++++++
>>  2 files changed, 22 insertions(+)
>>=20
>> diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
>> index 934402f5e9e6..17d2f18a1fd1 100644
>> --- a/fs/ceph/dir.c
>> +++ b/fs/ceph/dir.c
>> @@ -1069,6 +1069,15 @@ static int ceph_mkdir(struct user_namespace *mnt_=
userns, struct inode *dir,
>>  		op =3D CEPH_MDS_OP_MKSNAP;
>>  		dout("mksnap dir %p snap '%pd' dn %p\n", dir,
>>  		     dentry, dentry);
>> +		/*
>> +		 * Encrypted snapshots require d_revalidate to force a
>> +		 * LOOKUPSNAP to cleanup dcache
>> +		 */
>> +		if (IS_ENCRYPTED(dir)) {
>> +			spin_lock(&dentry->d_lock);
>> +			dentry->d_flags |=3D DCACHE_NOKEY_NAME;
>> +			spin_unlock(&dentry->d_lock);
>> +		}
>>  	} else if (ceph_snap(dir) =3D=3D CEPH_NOSNAP) {
>>  		dout("mkdir dir %p dn %p mode 0%ho\n", dir, dentry, mode);
>>  		op =3D CEPH_MDS_OP_MKDIR;
>> diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
>> index 8b0832271fdf..357335a11384 100644
>> --- a/fs/ceph/inode.c
>> +++ b/fs/ceph/inode.c
>> @@ -182,6 +182,19 @@ struct inode *ceph_get_snapdir(struct inode *parent)
>>  	ci->i_rbytes =3D 0;
>>  	ci->i_btime =3D ceph_inode(parent)->i_btime;
>>=20=20
>> +	/* if encrypted, just borrow fscrypt_auth from parent */
>> +	if (IS_ENCRYPTED(parent)) {
>> +		struct ceph_inode_info *pci =3D ceph_inode(parent);
>> +
>> +		ci->fscrypt_auth =3D kmemdup(pci->fscrypt_auth,
>> +					   pci->fscrypt_auth_len,
>> +					   GFP_KERNEL);
>> +		if (ci->fscrypt_auth) {
>> +			inode->i_flags |=3D S_ENCRYPTED;
>> +			ci->fscrypt_auth_len =3D pci->fscrypt_auth_len;
>> +		} else
>> +			dout("Failed to alloc memory for fscrypt_auth in snapdir\n");
>
> Should we return an error in this case?

Yeah, definitely.  I'll add that and send out v2.  Thanks.

Cheers,
--=20
Lu=C3=ADs


>
>> +	}
>>  	if (inode->i_state & I_NEW) {
>>  		inode->i_op =3D &ceph_snapdir_iops;
>>  		inode->i_fop =3D &ceph_snapdir_fops;
>
> Seems simple and straightforward at first glance.
> --=20
> Jeff Layton <jlayton@kernel.org>