From: Eric Biggers Subject: Re: [PATCH 5/6] fscrypt: cache the HMAC transform for each master key Date: Wed, 19 Jul 2017 10:37:44 -0700 Message-ID: <20170719173744.GB78811@gmail.com> References: <20170712210035.51534-1-ebiggers3@gmail.com> <20170712210035.51534-6-ebiggers3@gmail.com> <20170717174551.GA32282@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fscrypt@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org, linux-crypto@vger.kernel.org, "Theodore Y . Ts'o" , Jaegeuk Kim , Alex Cope , Eric Biggers To: Michael Halcrow Return-path: Received: from mail-pf0-f195.google.com ([209.85.192.195]:34978 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754553AbdGSRhr (ORCPT ); Wed, 19 Jul 2017 13:37:47 -0400 Content-Disposition: inline In-Reply-To: <20170717174551.GA32282@google.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, Jul 17, 2017 at 10:45:51AM -0700, Michael Halcrow wrote: > > +/* > > + * Get the fscrypt_master_key identified by the specified v2+ encryption > > + * context, or create it if not found. > > + * > > + * Returns the fscrypt_master_key with a reference taken, or an ERR_PTR(). > > + */ > > +static struct fscrypt_master_key * > > +find_or_create_master_key(const struct inode *inode, > > + const struct fscrypt_context *ctx, > > + unsigned int min_keysize) > > +{ > > + struct fscrypt_master_key *master_key; > > + > > + if (WARN_ON(ctx->version < FSCRYPT_CONTEXT_V2)) > > + return ERR_PTR(-EINVAL); > > Isn't this a programming error? If so, consider either BUG_ON() or > omit the check. > Yes, but BUG_ON() is discouraged in cases where there is a straightforward way to recover from the error. checkpatch actually warns about using it these days. Eric