From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1F8A272 for ; Wed, 11 Aug 2021 18:45:17 +0000 (UTC) Received: from fraeml702-chm.china.huawei.com (unknown [172.18.147.206]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4GlJdj4VsCz6BF7l; Thu, 12 Aug 2021 02:44:41 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml702-chm.china.huawei.com (10.206.15.51) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.8; Wed, 11 Aug 2021 20:45:14 +0200 Received: from localhost (10.52.123.85) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Wed, 11 Aug 2021 19:45:13 +0100 Date: Wed, 11 Aug 2021 19:44:43 +0100 From: Jonathan Cameron To: Dan Williams CC: , , , , , Subject: Re: [PATCH 04/23] libnvdimm/labels: Add a checksum calculation helper Message-ID: <20210811194443.00005e60@Huawei.com> In-Reply-To: <162854808885.1980150.16357075479454603275.stgit@dwillia2-desk3.amr.corp.intel.com> References: <162854806653.1980150.3354618413963083778.stgit@dwillia2-desk3.amr.corp.intel.com> <162854808885.1980150.16357075479454603275.stgit@dwillia2-desk3.amr.corp.intel.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; i686-w64-mingw32) Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.52.123.85] X-ClientProxiedBy: lhreml716-chm.china.huawei.com (10.201.108.67) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected On Mon, 9 Aug 2021 15:28:08 -0700 Dan Williams wrote: > In preparation for LIBNVDIMM to manage labels on CXL devices deploy > helpers that abstract the label type from the implementation. The CXL > label format is mostly similar to the EFI label format with concepts / > fields added, like dynamic region creation and label type guids, and > other concepts removed like BLK-mode and interleave-set-cookie ids. > > CXL labels support checksums by default, but early versions of the EFI > labels did not. Add a validate function that can return true in the case > the label format does not implement a checksum. > > Signed-off-by: Dan Williams Reviewed-by: Jonathan Cameron > --- > drivers/nvdimm/label.c | 68 +++++++++++++++++++++++++----------------------- > 1 file changed, 35 insertions(+), 33 deletions(-) > > diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c > index b40a4eda1d89..3f73412dd438 100644 > --- a/drivers/nvdimm/label.c > +++ b/drivers/nvdimm/label.c > @@ -346,29 +346,45 @@ static bool preamble_next(struct nvdimm_drvdata *ndd, > free, nslot); > } > > +static bool nsl_validate_checksum(struct nvdimm_drvdata *ndd, > + struct nd_namespace_label *nd_label) > +{ > + u64 sum, sum_save; > + > + if (!namespace_label_has(ndd, checksum)) > + return true; > + > + sum_save = nsl_get_checksum(ndd, nd_label); > + nsl_set_checksum(ndd, nd_label, 0); > + sum = nd_fletcher64(nd_label, sizeof_namespace_label(ndd), 1); > + nsl_set_checksum(ndd, nd_label, sum_save); > + return sum == sum_save; > +} > + > +static void nsl_calculate_checksum(struct nvdimm_drvdata *ndd, > + struct nd_namespace_label *nd_label) > +{ > + u64 sum; > + > + if (!namespace_label_has(ndd, checksum)) > + return; > + nsl_set_checksum(ndd, nd_label, 0); > + sum = nd_fletcher64(nd_label, sizeof_namespace_label(ndd), 1); > + nsl_set_checksum(ndd, nd_label, sum); > +} > + > static bool slot_valid(struct nvdimm_drvdata *ndd, > struct nd_namespace_label *nd_label, u32 slot) > { > + bool valid; > + > /* check that we are written where we expect to be written */ > if (slot != nsl_get_slot(ndd, nd_label)) > return false; > - > - /* check checksum */ > - if (namespace_label_has(ndd, checksum)) { > - u64 sum, sum_save; > - > - sum_save = nsl_get_checksum(ndd, nd_label); > - nsl_set_checksum(ndd, nd_label, 0); > - sum = nd_fletcher64(nd_label, sizeof_namespace_label(ndd), 1); > - nsl_set_checksum(ndd, nd_label, sum_save); > - if (sum != sum_save) { > - dev_dbg(ndd->dev, "fail checksum. slot: %d expect: %#llx\n", > - slot, sum); > - return false; > - } > - } > - > - return true; > + valid = nsl_validate_checksum(ndd, nd_label); > + if (!valid) > + dev_dbg(ndd->dev, "fail checksum. slot: %d\n", slot); > + return valid; > } > > int nd_label_reserve_dpa(struct nvdimm_drvdata *ndd) > @@ -812,13 +828,7 @@ static int __pmem_label_update(struct nd_region *nd_region, > guid_copy(&nd_label->abstraction_guid, > to_abstraction_guid(ndns->claim_class, > &nd_label->abstraction_guid)); > - if (namespace_label_has(ndd, checksum)) { > - u64 sum; > - > - nsl_set_checksum(ndd, nd_label, 0); > - sum = nd_fletcher64(nd_label, sizeof_namespace_label(ndd), 1); > - nsl_set_checksum(ndd, nd_label, sum); > - } > + nsl_calculate_checksum(ndd, nd_label); > nd_dbg_dpa(nd_region, ndd, res, "\n"); > > /* update label */ > @@ -1049,15 +1059,7 @@ static int __blk_label_update(struct nd_region *nd_region, > guid_copy(&nd_label->abstraction_guid, > to_abstraction_guid(ndns->claim_class, > &nd_label->abstraction_guid)); > - > - if (namespace_label_has(ndd, checksum)) { > - u64 sum; > - > - nsl_set_checksum(ndd, nd_label, 0); > - sum = nd_fletcher64(nd_label, > - sizeof_namespace_label(ndd), 1); > - nsl_set_checksum(ndd, nd_label, sum); > - } > + nsl_calculate_checksum(ndd, nd_label); > > /* update label */ > offset = nd_label_offset(ndd, nd_label); >