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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 41573C433EF for ; Fri, 15 Oct 2021 06:23:04 +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 0328160EE9 for ; Fri, 15 Oct 2021 06:23:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 0328160EE9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=5OTt6qJfAtFSe2W78w+lFmrymd3G+sVl1RmU9RKw+4k=; b=vTLUkG35DcgCbL Ai8IMUh6AViBcMEkppYj0RvwCU4Khc2KQ7+2LlkOHduQuPQN0nXL8DwUusDleKBClGdiHScTJyzRw Z64lCTB+8GZ7j/0xRSlGe5jdkoBKP8b/NerpS6IXTn/ITxZ+mcep0h30uc84dl5kK0DECu+wXe356 DuqdP8xEU1DX4wKFeYOzsUK0qe8EhikYL1SONpeL/sHgmu4bvsEORr/znMhUtvfHS52vAd1JNbQS3 K8zj//hpLxRiV3wYp9XKQKull5OjAAimspFeYcpmtB0iMLMxZ2ytvG3qtAeSu+KKTQf4nYl+eQykZ JhUyE9x9HDUmOYvf+05w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mbGbg-005VXk-6A; Fri, 15 Oct 2021 06:22:16 +0000 Received: from relay7-d.mail.gandi.net ([217.70.183.200]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mbGbd-005VWY-Oj for linux-mtd@lists.infradead.org; Fri, 15 Oct 2021 06:22:15 +0000 Received: (Authenticated sender: miquel.raynal@bootlin.com) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id 49C9020002; Fri, 15 Oct 2021 06:22:08 +0000 (UTC) Date: Fri, 15 Oct 2021 08:22:06 +0200 From: Miquel Raynal To: Boris Brezillon Cc: Sean Nyekjaer , Richard Weinberger , Vignesh Raghavendra , Boris Brezillon , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/3] mtd: core: protect access to mtd devices while in suspend Message-ID: <20211015082206.244a2316@xps13> In-Reply-To: <20211011160546.707b737b@collabora.com> References: <20211011115253.38497-1-sean@geanix.com> <20211011160546.707b737b@collabora.com> Organization: Bootlin X-Mailer: Claws Mail 3.17.7 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211014_232213_966686_E2885286 X-CRM114-Status: GOOD ( 26.37 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 SGkgU2VhbiwKCmJvcmlzLmJyZXppbGxvbkBjb2xsYWJvcmEuY29tIHdyb3RlIG9uIE1vbiwgMTEg T2N0IDIwMjEgMTY6MDU6NDYgKzAyMDA6Cgo+IE9uIE1vbiwgMTEgT2N0IDIwMjEgMTM6NTI6NTAg KzAyMDAKPiBTZWFuIE55ZWtqYWVyIDxzZWFuQGdlYW5peC5jb20+IHdyb3RlOgo+IAo+ID4gRm9s bG93LXVwIG9uIGRpc2N1c3Npb24gaW4gaHR0cHM6Ly9sa21sLm9yZy9sa21sLzIwMjEvMTAvNC80 MQo+ID4gCj4gPiBDaGFuZ2VzIHNpbmNlIGZyb20gcmZjIHYxL3YyOgo+ID4gIC0gYWRkZWQgYWNj ZXNzIHByb3RlY3Rpb24gZm9yIGFsbCBkZXZpY2UgYWNjZXNzIGhvb2tzIGluIG10ZF9pbmZvLgo+ ID4gIC0gYWRkZWQgU3VnZ2VzdGVkLWJ5IHRvIFsxLzNdIHBhdGNoLgo+ID4gIC0gcmVtb3ZlZCBy ZWZlcmVjZXMgdG8gY29tbWl0IGVmMzQ3YzBjZmQ2MSAoIm10ZDogcmF3bmFuZDogZ3BtaTogSW1w bGVtZW50IGV4ZWNfb3AiKQo+ID4gICAgZnJvbSBjb21taXQgbXNnIGFzIGNvbW1pdCAwMTNlNjI5 MmFhZjUgKCJtdGQ6IHJhd25hbmQ6IFNpbXBsaWZ5IHRoZSBsb2NraW5nIikgaXMgCj4gPiAgICB0 byBiZSBibGFtZWQuCj4gPiAgLSB0ZXN0ZWQgb24gYSBrZXJuZWwgd2l0aCBMT0NLREVQIGVuYWJs ZWQuCj4gPiAKPiA+IEBNaXF1ZWw6IEkgaGF2bid0IGNvdmVyZWQgZXZlcnkgaW9jdGwsIHRvIG1l IGl0IGxvb2tzIGxpa2UgdGhleSBoYXZuJ3QKPiA+IGRpcmVjdCBkZXZpY2UgYWNjZXNzLgoKWWVz IGluZGVlZCBpdCBsb29rcyBsaWtlIHRoZXkgcmUtdXNlIG1vc3Qgb2YgdGhlIG10ZGNvcmUuYyBm dW5jdGlvbnMsCnNvIGl0IHNob3VsZCBiZSBmaW5lLgoKPiA+IE9uZSAoc21hbGwpIGlzc3VlIHN0 aWxsIHByZXNlbnQuIGdwbWlfbmFuZC5jIHVzZXMgdGhlIHJ3c2VtIGJlZm9yZSBpdCdzCj4gPiBp bml0aWFsaXplZC4gU2VlbXMgY3VtYmVyc29tZSB0byBoYXZlIGV2ZXJ5IG10ZC9uYW5kIGRyaXZl ciB0byBjYWxsCj4gPiBpbml0X3dhaXRxdWV1ZV9oZWFkKCkgYW5kIGluaXRfcndzZW0oKS4gQ291 bGQgd2Ugc29tZWhvdyBtb3ZlIHRoZSBjYWxsCj4gPiB0byBtdGRfc2V0X2Rldl9kZWZhdWx0cygp IGJlZm9yZSBuYW5kX2NyZWF0ZV9iYnQoKT8gIAo+IAo+IEkgaGF2ZSBhIG5hc3R5IHRyaWNrIGZv ciB0aGF0IG9uZSwgYnV0IEknbSBub3Qgc3VyZSBNaXF1ZWwgd2lsbCBsaWtlIGl0Cj4gKGFjdHVh bGx5LCBJIGRvbid0IGxpa2UgaXQgZWl0aGVyLCBidXQgaXQncyBzbyBzaW1wbGUgY29tcGFyZWQg dG8gdGhlCj4gb3RoZXIgb3B0aW9ucyB3ZSBoYXZlIHRoYXQgSSdtIHRlbXB0ZWQgdG8gZ28gZm9y IHRoaXMgYXBwcm9hY2ggdW50aWwKPiBzb21lb25lIGhhcyB0aW1lIHRvIGludmVzdCBpbiBhIGNs ZWFuZXIgc29sdXRpb24gOi0pKToKPiAKPiBkaWZmIC0tZ2l0IGEvZHJpdmVycy9tdGQvbmFuZC9y YXcvbmFuZF9iYXNlLmMgYi9kcml2ZXJzL210ZC9uYW5kL3Jhdy9uYW5kX2Jhc2UuYwo+IGluZGV4 IDNkNmM2ZTg4MDUyMC4uYTlhYzJkNTI4YTRkIDEwMDY0NAo+IC0tLSBhL2RyaXZlcnMvbXRkL25h bmQvcmF3L25hbmRfYmFzZS5jCj4gKysrIGIvZHJpdmVycy9tdGQvbmFuZC9yYXcvbmFuZF9iYXNl LmMKPiBAQCAtNjIyMiw4ICs2MjIyLDYgQEAgc3RhdGljIGludCBuYW5kX3NjYW5fdGFpbChzdHJ1 Y3QgbmFuZF9jaGlwICpjaGlwKQo+ICAgICAgICAgbXRkLT5fc3luYyA9IG5hbmRfc3luYzsKPiAg ICAgICAgIG10ZC0+X2xvY2sgPSBuYW5kX2xvY2s7Cj4gICAgICAgICBtdGQtPl91bmxvY2sgPSBu YW5kX3VubG9jazsKPiAtICAgICAgIG10ZC0+X3N1c3BlbmQgPSBuYW5kX3N1c3BlbmQ7Cj4gLSAg ICAgICBtdGQtPl9yZXN1bWUgPSBuYW5kX3Jlc3VtZTsKPiAgICAgICAgIG10ZC0+X3JlYm9vdCA9 IG5hbmRfc2h1dGRvd247Cj4gICAgICAgICBtdGQtPl9ibG9ja19pc3Jlc2VydmVkID0gbmFuZF9i bG9ja19pc3Jlc2VydmVkOwo+ICAgICAgICAgbXRkLT5fYmxvY2tfaXNiYWQgPSBuYW5kX2Jsb2Nr X2lzYmFkOwo+IEBAIC02MjY5LDYgKzYyNjcsMTMgQEAgc3RhdGljIGludCBuYW5kX3NjYW5fdGFp bChzdHJ1Y3QgbmFuZF9jaGlwICpjaGlwKQo+ICAgICAgICAgaWYgKHJldCkKPiAgICAgICAgICAg ICAgICAgZ290byBlcnJfZnJlZV9zZWN1cmVfcmVnaW9uczsKPiAgCj4gKyAgICAgICAvKgo+ICsg ICAgICAgICogUG9wdWxhdGUgdGhlIHN1c3BlbmQvcmVzdW1lIGhvb2tzIGFmdGVyIHRoZSBCQlQg aGFzIGJlZW4gc2Nhbm5lZCB0bwo+ICsgICAgICAgICogYXZvaWQgdXNpbmcgdGhlIHN1c3BlbmQg bG9jayBhbmQgcmVzdW1lIHdhaXRxdWV1ZSB3aGljaCBhcmUgb25seQo+ICsgICAgICAgICogaW5p dGlhbGl6ZWQgd2hlbiBtdGRfZGV2aWNlX3JlZ2lzdGVyKCkgaXMgY2FsbGVkLgo+ICsgICAgICAg ICovCj4gKyAgICAgICBtdGQtPl9zdXNwZW5kID0gbmFuZF9zdXNwZW5kOwo+ICsgICAgICAgbXRk LT5fcmVzdW1lID0gbmFuZF9yZXN1bWU7Cj4gICAgICAgICByZXR1cm4gMDsKCkknbSBmaW5lIHdp dGggdGhpcyBhcyBsb25nIGFzIGl0IGlzIGRvY3VtZW50ZWQgZm9yIG5vdy4KClRoYW5rcywKTWlx dcOobAoKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fCkxpbnV4IE1URCBkaXNjdXNzaW9uIG1haWxpbmcgbGlzdApodHRwOi8vbGlzdHMuaW5mcmFk ZWFkLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2xpbnV4LW10ZC8K 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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 43AA6C433F5 for ; Fri, 15 Oct 2021 06:22:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 14C3760EE5 for ; Fri, 15 Oct 2021 06:22:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234311AbhJOGYS convert rfc822-to-8bit (ORCPT ); Fri, 15 Oct 2021 02:24:18 -0400 Received: from relay7-d.mail.gandi.net ([217.70.183.200]:41373 "EHLO relay7-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232124AbhJOGYQ (ORCPT ); Fri, 15 Oct 2021 02:24:16 -0400 Received: (Authenticated sender: miquel.raynal@bootlin.com) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id 49C9020002; Fri, 15 Oct 2021 06:22:08 +0000 (UTC) Date: Fri, 15 Oct 2021 08:22:06 +0200 From: Miquel Raynal To: Boris Brezillon Cc: Sean Nyekjaer , Richard Weinberger , Vignesh Raghavendra , Boris Brezillon , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/3] mtd: core: protect access to mtd devices while in suspend Message-ID: <20211015082206.244a2316@xps13> In-Reply-To: <20211011160546.707b737b@collabora.com> References: <20211011115253.38497-1-sean@geanix.com> <20211011160546.707b737b@collabora.com> Organization: Bootlin X-Mailer: Claws Mail 3.17.7 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Sean, boris.brezillon@collabora.com wrote on Mon, 11 Oct 2021 16:05:46 +0200: > On Mon, 11 Oct 2021 13:52:50 +0200 > Sean Nyekjaer wrote: > > > Follow-up on discussion in https://lkml.org/lkml/2021/10/4/41 > > > > Changes since from rfc v1/v2: > > - added access protection for all device access hooks in mtd_info. > > - added Suggested-by to [1/3] patch. > > - removed refereces to commit ef347c0cfd61 ("mtd: rawnand: gpmi: Implement exec_op") > > from commit msg as commit 013e6292aaf5 ("mtd: rawnand: Simplify the locking") is > > to be blamed. > > - tested on a kernel with LOCKDEP enabled. > > > > @Miquel: I havn't covered every ioctl, to me it looks like they havn't > > direct device access. Yes indeed it looks like they re-use most of the mtdcore.c functions, so it should be fine. > > One (small) issue still present. gpmi_nand.c uses the rwsem before it's > > initialized. Seems cumbersome to have every mtd/nand driver to call > > init_waitqueue_head() and init_rwsem(). Could we somehow move the call > > to mtd_set_dev_defaults() before nand_create_bbt()? > > I have a nasty trick for that one, but I'm not sure Miquel will like it > (actually, I don't like it either, but it's so simple compared to the > other options we have that I'm tempted to go for this approach until > someone has time to invest in a cleaner solution :-)): > > diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c > index 3d6c6e880520..a9ac2d528a4d 100644 > --- a/drivers/mtd/nand/raw/nand_base.c > +++ b/drivers/mtd/nand/raw/nand_base.c > @@ -6222,8 +6222,6 @@ static int nand_scan_tail(struct nand_chip *chip) > mtd->_sync = nand_sync; > mtd->_lock = nand_lock; > mtd->_unlock = nand_unlock; > - mtd->_suspend = nand_suspend; > - mtd->_resume = nand_resume; > mtd->_reboot = nand_shutdown; > mtd->_block_isreserved = nand_block_isreserved; > mtd->_block_isbad = nand_block_isbad; > @@ -6269,6 +6267,13 @@ static int nand_scan_tail(struct nand_chip *chip) > if (ret) > goto err_free_secure_regions; > > + /* > + * Populate the suspend/resume hooks after the BBT has been scanned to > + * avoid using the suspend lock and resume waitqueue which are only > + * initialized when mtd_device_register() is called. > + */ > + mtd->_suspend = nand_suspend; > + mtd->_resume = nand_resume; > return 0; I'm fine with this as long as it is documented for now. Thanks, Miquèl