From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Weinberger Subject: Re: [RFC PATCH v3 04/18] fs: add ->s_master_keys to struct super_block Date: Thu, 21 Feb 2019 00:19:54 +0100 Message-ID: References: <20190220065249.32099-1-ebiggers@kernel.org> <20190220065249.32099-5-ebiggers@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-2.v29.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1gwb9z-0005xX-EO for linux-f2fs-devel@lists.sourceforge.net; Wed, 20 Feb 2019 23:20:15 +0000 Received: from mail-wm1-f66.google.com ([209.85.128.66]) by sfi-mx-3.v28.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.90_1) id 1gwb9x-0047vm-FJ for linux-f2fs-devel@lists.sourceforge.net; Wed, 20 Feb 2019 23:20:15 +0000 Received: by mail-wm1-f66.google.com with SMTP id n19so8335673wmi.1 for ; Wed, 20 Feb 2019 15:20:13 -0800 (PST) In-Reply-To: <20190220065249.32099-5-ebiggers@kernel.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: Eric Biggers Cc: Satya Tangirala , "open list:ABI/API" , linux-f2fs-devel@lists.sourceforge.net, linux-fscrypt@vger.kernel.org, keyrings@vger.kernel.org, linux-mtd@lists.infradead.org, linux-crypto@vger.kernel.org, linux-fsdevel , linux-ext4@vger.kernel.org, Paul Crowley On Wed, Feb 20, 2019 at 7:55 AM Eric Biggers wrote: > > From: Eric Biggers > > Add an ->s_master_keys keyring to 'struct super_block'. New fscrypt > ioctls will allow adding and removing encryption keys from this keyring. > This will enable solving multiple interrelated problems with how fscrypt > keys are provided and managed currently, including: > > - Making the key status (which is currently per-process) match the > filesystem-level status of which encrypted files are "unlocked". > > - Supporting a proper API to remove encryption keys, "locking" the > corresponding encrypted files. > > - Caching an HMAC transform for each master key, allowing the use of > HKDF while still retaining good performance. > > - Preventing denial of service via keyctl_invalidate(). > > Similar to the existing ->s_cop, the keyring is added to the VFS-level > superblock struct rather than separately to the ext4, f2fs, and ubifs > superblock structs so that it can be used by the shared code in > fs/crypto/. To minimize overhead, the keyring will only be allocated if > userspace actually adds a key; otherwise will stay NULL. > > Signed-off-by: Eric Biggers > --- > fs/super.c | 3 +++ > include/linux/fs.h | 1 + > 2 files changed, 4 insertions(+) > > diff --git a/fs/super.c b/fs/super.c > index 48e25eba8465..7ca05dda905c 100644 > --- a/fs/super.c > +++ b/fs/super.c > @@ -291,6 +291,9 @@ static void __put_super(struct super_block *s) > security_sb_free(s); > put_user_ns(s->s_user_ns); > kfree(s->s_subtype); > +#ifdef CONFIG_FS_ENCRYPTION > + key_put(s->s_master_keys); > +#endif Please wrap this in a static inline function such that you can get rid of the ifdef here. Just like put_user_ns() does. -- Thanks, //richard