From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D6F4EC43144 for ; Wed, 27 Jun 2018 11:45:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8D4E72613D for ; Wed, 27 Jun 2018 11:45:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8D4E72613D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964862AbeF0Lo7 (ORCPT ); Wed, 27 Jun 2018 07:44:59 -0400 Received: from mail.bootlin.com ([62.4.15.54]:37306 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753597AbeF0Lo6 (ORCPT ); Wed, 27 Jun 2018 07:44:58 -0400 Received: by mail.bootlin.com (Postfix, from userid 110) id F041F2079D; Wed, 27 Jun 2018 13:44:55 +0200 (CEST) Received: from bbrezillon (AAubervilliers-681-1-87-188.w90-88.abo.wanadoo.fr [90.88.29.188]) by mail.bootlin.com (Postfix) with ESMTPSA id AACA920714; Wed, 27 Jun 2018 13:44:55 +0200 (CEST) Date: Wed, 27 Jun 2018 13:44:56 +0200 From: Boris Brezillon To: Quentin Schulz Cc: dedekind1@gmail.com, richard@nod.at, dwmw2@infradead.org, computersforpeace@gmail.com, marek.vasut@gmail.com, linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, thomas.petazzoni@bootlin.com Subject: Re: [PATCH v2 1/2] ubi: provide a way to skip CRC checks Message-ID: <20180627134456.522a1c96@bbrezillon> In-Reply-To: References: X-Mailer: Claws Mail 3.15.0-dirty (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 27 Jun 2018 13:33:19 +0200 Quentin Schulz wrote: > Some users of static UBI volumes implement their own integrity check, > thus making the volume CRC check done at open time useless. For > instance, this is the case when one use the ubiblock + dm-verity + > squashfs combination, where dm-verity already checks integrity of the > block device but this time at the block granularity instead of verifying > the whole volume. > > Skipping this test drastically improves the boot-time. > > Suggested-by: Boris Brezillon > Signed-off-by: Quentin Schulz Just a few minor comments (see below). Reviewed-by: Boris Brezillon > --- > drivers/mtd/ubi/kapi.c | 2 +- > drivers/mtd/ubi/ubi-media.h | 6 ++++++ > drivers/mtd/ubi/ubi.h | 4 ++++ > drivers/mtd/ubi/vmt.c | 9 +++++++++ > drivers/mtd/ubi/vtbl.c | 3 +++ > 5 files changed, 23 insertions(+), 1 deletion(-) > > diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c > index d4b2e87..e9e9ecb 100644 > --- a/drivers/mtd/ubi/kapi.c > +++ b/drivers/mtd/ubi/kapi.c > @@ -202,7 +202,7 @@ struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode) > desc->mode = mode; > > mutex_lock(&ubi->ckvol_mutex); > - if (!vol->checked) { > + if (!vol->checked && !vol->skip_check) { > /* This is the first open - check the volume */ > err = ubi_check_volume(ubi, vol_id); > if (err < 0) { > diff --git a/drivers/mtd/ubi/ubi-media.h b/drivers/mtd/ubi/ubi-media.h > index 195ff8c..f43a4ff 100644 > --- a/drivers/mtd/ubi/ubi-media.h > +++ b/drivers/mtd/ubi/ubi-media.h > @@ -45,6 +45,11 @@ enum { > * Volume flags used in the volume table record. > * > * @UBI_VTBL_AUTORESIZE_FLG: auto-resize this volume > + * @UBI_VTBL_SKIP_CRC_CHECK_FLG: skip the CRC check done on static volume at ^ volumes? > + * open time. Should only be set on volumes that > + * are used by upper layers doing this kind of > + * check. Main use-case for this flag is > + * boot-time reduction > * > * %UBI_VTBL_AUTORESIZE_FLG flag can be set only for one volume in the volume > * table. UBI automatically re-sizes the volume which has this flag and makes > @@ -76,6 +81,7 @@ enum { > */ > enum { > UBI_VTBL_AUTORESIZE_FLG = 0x01, > + UBI_VTBL_SKIP_CRC_CHECK_FLG = 0x02, > }; > > /* > diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h > index f5ba97c..429102b 100644 > --- a/drivers/mtd/ubi/ubi.h > +++ b/drivers/mtd/ubi/ubi.h > @@ -327,6 +327,9 @@ struct ubi_eba_leb_desc { > * atomic LEB change > * > * @eba_tbl: EBA table of this volume (LEB->PEB mapping) > + * @skip_check: %1 if CRC check of static volumes should be skipped. Directly > + * reflect the presence of the %UBI_VTBL_SKIP_CRC_CHECK_FLG in the ^ reflects? ^ %UBI_VTBL_SKIP_CRC_CHECK_FLG *flag* in > + * vtbl entry > * @checked: %1 if this static volume was checked > * @corrupted: %1 if the volume is corrupted (static volumes only) > * @upd_marker: %1 if the update marker is set for this volume > @@ -374,6 +377,7 @@ struct ubi_volume { > void *upd_buf; > > struct ubi_eba_table *eba_tbl; > + unsigned int skip_check:1; > unsigned int checked:1; > unsigned int corrupted:1; > unsigned int upd_marker:1; > diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c > index 0be5167..e2606a4 100644 > --- a/drivers/mtd/ubi/vmt.c > +++ b/drivers/mtd/ubi/vmt.c > @@ -299,6 +299,10 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req) > vtbl_rec.vol_type = UBI_VID_DYNAMIC; > else > vtbl_rec.vol_type = UBI_VID_STATIC; > + > + if (vol->skip_check) > + vtbl_rec.flags |= UBI_VTBL_SKIP_CRC_CHECK_FLG; > + > memcpy(vtbl_rec.name, vol->name, vol->name_len); > > err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec); > @@ -733,6 +737,11 @@ static int self_check_volume(struct ubi_device *ubi, int vol_id) > ubi_err(ubi, "bad used_bytes"); > goto fail; > } > + > + if (vol->skip_check) { > + ubi_err(ubi, "bad skip_check"); > + goto fail; > + } > } else { > if (vol->used_ebs < 0 || vol->used_ebs > vol->reserved_pebs) { > ubi_err(ubi, "bad used_ebs"); > diff --git a/drivers/mtd/ubi/vtbl.c b/drivers/mtd/ubi/vtbl.c > index 94d7a86..2c133cd 100644 > --- a/drivers/mtd/ubi/vtbl.c > +++ b/drivers/mtd/ubi/vtbl.c > @@ -560,6 +560,9 @@ static int init_volumes(struct ubi_device *ubi, > vol->name[vol->name_len] = '\0'; > vol->vol_id = i; > > + if (vtbl[i].flags & UBI_VTBL_SKIP_CRC_CHECK_FLG) > + vol->skip_check = 1; > + > if (vtbl[i].flags & UBI_VTBL_AUTORESIZE_FLG) { > /* Auto re-size flag may be set only for one volume */ > if (ubi->autoresize_vol_id != -1) {