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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=no 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 D84A5C54FCE for ; Sun, 22 Mar 2020 10:28:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B82882072E for ; Sun, 22 Mar 2020 10:28:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726979AbgCVK2t (ORCPT ); Sun, 22 Mar 2020 06:28:49 -0400 Received: from smtp2207-205.mail.aliyun.com ([121.197.207.205]:53744 "EHLO smtp2207-205.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726866AbgCVK2t (ORCPT ); Sun, 22 Mar 2020 06:28:49 -0400 X-Alimail-AntiSpam: AC=CONTINUE;BC=0.07438739|-1;CH=green;DM=||false|;DS=CONTINUE|ham_regular_dialog|0.185973-0.000472118-0.813555;FP=0|0|0|0|0|-1|-1|-1;HT=e02c03311;MF=liaoweixiong@allwinnertech.com;NM=1;PH=DS;RN=16;RT=16;SR=0;TI=SMTPD_---.H3OteXN_1584872892; Received: from 172.16.10.102(mailfrom:liaoweixiong@allwinnertech.com fp:SMTPD_---.H3OteXN_1584872892) by smtp.aliyun-inc.com(10.147.41.137); Sun, 22 Mar 2020 18:28:13 +0800 Subject: Re: [PATCH v2 01/11] pstore/blk: new support logger for block devices To: Kees Cook Cc: Anton Vorontsov , Colin Cross , Tony Luck , Jonathan Corbet , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Mauro Carvalho Chehab , "David S. Miller" , Rob Herring , Greg Kroah-Hartman , Jonathan Cameron , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org References: <1581078355-19647-1-git-send-email-liaoweixiong@allwinnertech.com> <1581078355-19647-2-git-send-email-liaoweixiong@allwinnertech.com> <202002251626.63FE3E7C6@keescook> <5fd540be-6ed9-a1c7-4932-e67194dddca8@allwinnertech.com> <202003180944.3B36871@keescook> <202003201111.BE5EAB9A@keescook> From: WeiXiong Liao Message-ID: Date: Sun, 22 Mar 2020 18:28:22 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <202003201111.BE5EAB9A@keescook> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org hi Kees Cook, On 2020/3/21 上午2:20, Kees Cook wrote: > On Fri, Mar 20, 2020 at 09:50:36AM +0800, WeiXiong Liao wrote: >> On 2020/3/19 AM 1:23, Kees Cook wrote: >>> On Thu, Feb 27, 2020 at 04:21:51PM +0800, liaoweixiong wrote: >>>> On 2020/2/26 AM 8:52, Kees Cook wrote: >>>>> On Fri, Feb 07, 2020 at 08:25:45PM +0800, WeiXiong Liao wrote: >>>>>> +obj-$(CONFIG_PSTORE_BLK) += pstore_blk.o >>>>>> +pstore_blk-y += blkzone.o >>>>> >>>>> Why this dance with files? I would just expect: >>>>> >>>>> obj-$(CONFIG_PSTORE_BLK) += blkzone.o >>>>> >>>> >>>> This makes the built module named blkzone.ko rather than >>>> pstore_blk.ko. >>> >>> You can just do a regular build rule: >>> >>> obj-$(CONFIG_PSTORE_BLK) += blkzone.o >>> >> >> I don't get it. If make it as your words, the built module will be >> blkzone.ko. >> The module is named pstore/blk, however it built out blkzone.ko. I think >> it's confusing. > > I mean just pick whatever filename you want it to be named. The Makefile > case for ramoops was that ramoops got renamed but we wanted to keep the > old API name. > > So, if you want it named pstore-blk.ko, just rename blkzone.c to > pstore-blk.c. > How about rename blkzone.c to psotre_zone.c and blkoops.c to pstore_blk.c? Please refer to my reply email for patch 2. >>>>> If you're expecting concurrent writers (use of atomic_set(), I would >>>>> expect the whole write to be locked instead. (i.e. what happens if >>>>> multiple callers call blkz_zone_write()?) >>>>> >>>> >>>> I don't agree with it. The datalen will be updated everywhere. It's useless >>>> to lock here. >>> >>> But there could be multiple writers; locking should be needed. >>> >> >> All the recorders such as dmesg, pmsg, console and ftrace have been >> locked on >> pstore and upper layers. So, a recorder will not write in parallel and >> different >> recorders operate privately zone. They don't have any influence on each >> other. > > Yes, sorry, I was confusing myself about pmsg, and I forgot it had a > global lock. Each are locked or split by CPU. > >> The only parallel case I think is that recorder writes while dirty-flush >> thread is >> working. And the dirty-flusher will flush the whole zone rather than >> part of it, so, >> it is OK to call in parallel. > > Okay, thanks for clarifying. > >> Based on these reasons, I don't think locking should be needed. > > Agreed. > -- WeiXiong Liao 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=-2.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 90CAAC54FCF for ; Sun, 22 Mar 2020 10:28:50 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 664062072E for ; Sun, 22 Mar 2020 10:28:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="GfPStGfX" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 664062072E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=allwinnertech.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:To:Subject:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=hqueR2ik4Z4Wy0q69yOzg47FWaNjodK4zLK9gPqlCVQ=; b=GfPStGfXViePkF rbNxXhKu/qpzADWdZjrtA7dFlM/2hsf0zYZoaofQHuGgaBwmHmOrjH+MCEpNR0JN5gcKYvtKFeugp or3sn7hksfoXkJsKhgCXwJlXihop6l0TnI10olVrVm8qqsc+vJ2KCI0l15HTvn3W1fuZ8b76b1ezc sGrrhi0z0KO889mtys1RYD9NUcM8br1EYsko4hLVyq48a9iM39OthiGLU4W1MvC6/+ZCCo41TKfqL qsq5jwb9TK8MHLU2W4LlMC15vwrRdQdr2+YatpywOPz6x0Agv+tCfj9j+ZWXubAlz3HQD2+myB+o0 QS0I4vPqOlpOnf69oBbw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jFxqF-0003m3-0n; Sun, 22 Mar 2020 10:28:27 +0000 Received: from smtp2207-205.mail.aliyun.com ([121.197.207.205]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jFxq9-0003lE-VJ for linux-mtd@lists.infradead.org; Sun, 22 Mar 2020 10:28:25 +0000 X-Alimail-AntiSpam: AC=CONTINUE; BC=0.07438739|-1; CH=green; DM=||false|; DS=CONTINUE|ham_regular_dialog|0.185973-0.000472118-0.813555; FP=0|0|0|0|0|-1|-1|-1; HT=e02c03311; MF=liaoweixiong@allwinnertech.com; NM=1; PH=DS; RN=16; RT=16; SR=0; TI=SMTPD_---.H3OteXN_1584872892; Received: from 172.16.10.102(mailfrom:liaoweixiong@allwinnertech.com fp:SMTPD_---.H3OteXN_1584872892) by smtp.aliyun-inc.com(10.147.41.137); Sun, 22 Mar 2020 18:28:13 +0800 Subject: Re: [PATCH v2 01/11] pstore/blk: new support logger for block devices To: Kees Cook References: <1581078355-19647-1-git-send-email-liaoweixiong@allwinnertech.com> <1581078355-19647-2-git-send-email-liaoweixiong@allwinnertech.com> <202002251626.63FE3E7C6@keescook> <5fd540be-6ed9-a1c7-4932-e67194dddca8@allwinnertech.com> <202003180944.3B36871@keescook> <202003201111.BE5EAB9A@keescook> From: WeiXiong Liao Message-ID: Date: Sun, 22 Mar 2020 18:28:22 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <202003201111.BE5EAB9A@keescook> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200322_032822_196309_2F07E187 X-CRM114-Status: GOOD ( 16.02 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Rob Herring , Tony Luck , Vignesh Raghavendra , Jonathan Corbet , Richard Weinberger , Anton Vorontsov , linux-doc@vger.kernel.org, Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Colin Cross , linux-mtd@lists.infradead.org, Jonathan Cameron , Miquel Raynal , Mauro Carvalho Chehab , "David S. Miller" Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org aGkgS2VlcyBDb29rLAoKT24gMjAyMC8zLzIxIOS4iuWNiDI6MjAsIEtlZXMgQ29vayB3cm90ZToK PiBPbiBGcmksIE1hciAyMCwgMjAyMCBhdCAwOTo1MDozNkFNICswODAwLCBXZWlYaW9uZyBMaWFv IHdyb3RlOgo+PiBPbiAyMDIwLzMvMTkgQU0gMToyMywgS2VlcyBDb29rIHdyb3RlOgo+Pj4gT24g VGh1LCBGZWIgMjcsIDIwMjAgYXQgMDQ6MjE6NTFQTSArMDgwMCwgbGlhb3dlaXhpb25nIHdyb3Rl Ogo+Pj4+IE9uIDIwMjAvMi8yNiBBTSA4OjUyLCBLZWVzIENvb2sgd3JvdGU6Cj4+Pj4+IE9uIEZy aSwgRmViIDA3LCAyMDIwIGF0IDA4OjI1OjQ1UE0gKzA4MDAsIFdlaVhpb25nIExpYW8gd3JvdGU6 Cj4+Pj4+PiArb2JqLSQoQ09ORklHX1BTVE9SRV9CTEspICs9IHBzdG9yZV9ibGsubwo+Pj4+Pj4g K3BzdG9yZV9ibGsteSArPSBibGt6b25lLm8KPj4+Pj4KPj4+Pj4gV2h5IHRoaXMgZGFuY2Ugd2l0 aCBmaWxlcz8gSSB3b3VsZCBqdXN0IGV4cGVjdDoKPj4+Pj4KPj4+Pj4gb2JqLSQoQ09ORklHX1BT VE9SRV9CTEspICAgICArPSBibGt6b25lLm8KPj4+Pj4KPj4+Pgo+Pj4+IFRoaXMgbWFrZXMgdGhl IGJ1aWx0IG1vZHVsZSBuYW1lZCBibGt6b25lLmtvIHJhdGhlciB0aGFuCj4+Pj4gcHN0b3JlX2Js ay5rby4KPj4+Cj4+PiBZb3UgY2FuIGp1c3QgZG8gYSByZWd1bGFyIGJ1aWxkIHJ1bGU6Cj4+Pgo+ Pj4gb2JqLSQoQ09ORklHX1BTVE9SRV9CTEspICs9IGJsa3pvbmUubwo+Pj4KPj4KPj4gSSBkb24n dCBnZXQgaXQuIElmIG1ha2UgaXQgYXMgeW91ciB3b3JkcywgdGhlIGJ1aWx0IG1vZHVsZSB3aWxs IGJlCj4+IGJsa3pvbmUua28uCj4+IFRoZSBtb2R1bGUgaXMgbmFtZWQgcHN0b3JlL2JsaywgaG93 ZXZlciBpdCBidWlsdCBvdXQgYmxrem9uZS5rby4gSSB0aGluawo+PiBpdCdzIGNvbmZ1c2luZy4K PiAKPiBJIG1lYW4ganVzdCBwaWNrIHdoYXRldmVyIGZpbGVuYW1lIHlvdSB3YW50IGl0IHRvIGJl IG5hbWVkLiBUaGUgTWFrZWZpbGUKPiBjYXNlIGZvciByYW1vb3BzIHdhcyB0aGF0IHJhbW9vcHMg Z290IHJlbmFtZWQgYnV0IHdlIHdhbnRlZCB0byBrZWVwIHRoZQo+IG9sZCBBUEkgbmFtZS4KPiAK PiBTbywgaWYgeW91IHdhbnQgaXQgbmFtZWQgcHN0b3JlLWJsay5rbywganVzdCByZW5hbWUgYmxr em9uZS5jIHRvCj4gcHN0b3JlLWJsay5jLgo+IAoKSG93IGFib3V0IHJlbmFtZSBibGt6b25lLmMg dG8gcHNvdHJlX3pvbmUuYyBhbmQgYmxrb29wcy5jIHRvIHBzdG9yZV9ibGsuYz8KClBsZWFzZSBy ZWZlciB0byBteSByZXBseSBlbWFpbCBmb3IgcGF0Y2ggMi4KCj4+Pj4+IElmIHlvdSdyZSBleHBl Y3RpbmcgY29uY3VycmVudCB3cml0ZXJzICh1c2Ugb2YgYXRvbWljX3NldCgpLCBJIHdvdWxkCj4+ Pj4+IGV4cGVjdCB0aGUgd2hvbGUgd3JpdGUgdG8gYmUgbG9ja2VkIGluc3RlYWQuIChpLmUuIHdo YXQgaGFwcGVucyBpZgo+Pj4+PiBtdWx0aXBsZSBjYWxsZXJzIGNhbGwgYmxrel96b25lX3dyaXRl KCk/KQo+Pj4+Pgo+Pj4+Cj4+Pj4gSSBkb24ndCBhZ3JlZSB3aXRoIGl0LiBUaGUgZGF0YWxlbiB3 aWxsIGJlIHVwZGF0ZWQgZXZlcnl3aGVyZS4gSXQncyB1c2VsZXNzCj4+Pj4gdG8gbG9jayBoZXJl Lgo+Pj4KPj4+IEJ1dCB0aGVyZSBjb3VsZCBiZSBtdWx0aXBsZSB3cml0ZXJzOyBsb2NraW5nIHNo b3VsZCBiZSBuZWVkZWQuCj4+Pgo+Pgo+PiBBbGwgdGhlIHJlY29yZGVycyBzdWNoIGFzIGRtZXNn LCBwbXNnLCBjb25zb2xlIGFuZCBmdHJhY2UgaGF2ZSBiZWVuCj4+IGxvY2tlZCBvbgo+PiBwc3Rv cmUgYW5kIHVwcGVyIGxheWVycy4gU28sIGEgcmVjb3JkZXIgd2lsbCBub3Qgd3JpdGUgaW4gcGFy YWxsZWwgYW5kCj4+IGRpZmZlcmVudAo+PiByZWNvcmRlcnMgb3BlcmF0ZSBwcml2YXRlbHkgem9u ZS4gVGhleSBkb24ndCBoYXZlIGFueSBpbmZsdWVuY2Ugb24gZWFjaAo+PiBvdGhlci4KPiAKPiBZ ZXMsIHNvcnJ5LCBJIHdhcyBjb25mdXNpbmcgbXlzZWxmIGFib3V0IHBtc2csIGFuZCBJIGZvcmdv dCBpdCBoYWQgYQo+IGdsb2JhbCBsb2NrLiBFYWNoIGFyZSBsb2NrZWQgb3Igc3BsaXQgYnkgQ1BV Lgo+IAo+PiBUaGUgb25seSBwYXJhbGxlbCBjYXNlIEkgdGhpbmsgaXMgdGhhdCByZWNvcmRlciB3 cml0ZXMgd2hpbGUgZGlydHktZmx1c2gKPj4gdGhyZWFkIGlzCj4+IHdvcmtpbmcuIEFuZCB0aGUg ZGlydHktZmx1c2hlciB3aWxsIGZsdXNoIHRoZSB3aG9sZSB6b25lIHJhdGhlciB0aGFuCj4+IHBh cnQgb2YgaXQsIHNvLAo+PiBpdCBpcyBPSyB0byBjYWxsIGluIHBhcmFsbGVsLgo+IAo+IE9rYXks IHRoYW5rcyBmb3IgY2xhcmlmeWluZy4KPiAKPj4gQmFzZWQgb24gdGhlc2UgcmVhc29ucywgSSBk b24ndCB0aGluayBsb2NraW5nIHNob3VsZCBiZSBuZWVkZWQuCj4gCj4gQWdyZWVkLgo+IAoKLS0g CldlaVhpb25nIExpYW8KCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fXwpMaW51eCBNVEQgZGlzY3Vzc2lvbiBtYWlsaW5nIGxpc3QKaHR0cDovL2xp c3RzLmluZnJhZGVhZC5vcmcvbWFpbG1hbi9saXN0aW5mby9saW51eC1tdGQvCg==