From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heinz Mauelshagen Subject: Re: [dm-devel] [PATCH 1/1] dm raid: fix compat_features validation Date: Tue, 11 Oct 2016 17:44:21 +0200 Message-ID: <591b9d8d-2036-2d0f-14f2-af176b5beaea@redhat.com> References: <20161011142835.11620-1-apw@canonical.com> <1c517f14-1234-7844-fc6a-cd1b9698fb8b@redhat.com> <20161011153808.nmyf6hafjaadcemw@brain> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20161011153808.nmyf6hafjaadcemw@brain> Sender: linux-kernel-owner@vger.kernel.org To: Andy Whitcroft Cc: Mike Snitzer , linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, dm-devel@redhat.com, Shaohua Li , Alasdair Kergon List-Id: linux-raid.ids On 10/11/2016 05:38 PM, Andy Whitcroft wrote: > On Tue, Oct 11, 2016 at 05:04:34PM +0200, Heinz Mauelshagen wrote: >> Andy, >> >> good catch. >> >> We should rather check for V190 support only in case any >> compat feature flags are actually set. >> >> { >> + if (le32_to_cpu(sb->compat_features) && >> + le32_to_cpu(sb->compat_features) != FEATURE_FLAG_SUPPORTS_V190) >> { >> rs->ti->error = "Unable to assemble array: Unknown flag(s) >> in compatible feature flags"; >> return -EINVAL; >> } > If the feature flags are single bit combinations then I believe the > below does check exactly that. Checking for no 1s outside of the > expected features, caring not for the value of the valid bits: > > + if (le32_to_cpu(sb->compat_features) & ~(FEATURE_FLAG_SUPPORTS_V190)) { > > with the possibilty to or in additional feature bits as they are added. Thanks, I prefer this to be easier readable. > > -apw > > -- > dm-devel mailing list > dm-devel@redhat.com > https://www.redhat.com/mailman/listinfo/dm-devel