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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id E0B70C3064D for ; Tue, 2 Jul 2024 12:02:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 755B46B0095; Tue, 2 Jul 2024 08:02:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 705DC6B009D; Tue, 2 Jul 2024 08:02:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5A68E6B00A0; Tue, 2 Jul 2024 08:02:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 396816B0095 for ; Tue, 2 Jul 2024 08:02:58 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id E9686A20FF for ; 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d=hostedemail.com; t=1719921754; a=rsa-sha256; cv=none; b=PeTlHcEdIvvd/MxTsUHpAhjg6+N/wtualY6yoUxXb+A1uRV6/jolWb26ayjt3hz0xVU1lr 12QDkWPCYwNeyISFHyLTwRSODgPbLRkjvDgdMwukUElIdCbDCA+l0PF6I72R0ASPmxJlfB aLHN+enN5b1R9TpTLr4TZFQ7HfKq0qc= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf24.hostedemail.com: domain of hch@lst.de designates 213.95.11.211 as permitted sender) smtp.mailfrom=hch@lst.de Received: by verein.lst.de (Postfix, from userid 2407) id 1ABC168AA6; Tue, 2 Jul 2024 14:02:51 +0200 (CEST) Date: Tue, 2 Jul 2024 14:02:50 +0200 From: Christoph Hellwig To: "Pankaj Raghav (Samsung)" Cc: Christoph Hellwig , david@fromorbit.com, willy@infradead.org, chandan.babu@oracle.com, djwong@kernel.org, brauner@kernel.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, yang@os.amperecomputing.com, linux-mm@kvack.org, john.g.garry@oracle.com, linux-fsdevel@vger.kernel.org, hare@suse.de, p.raghav@samsung.com, mcgrof@kernel.org, gost.dev@samsung.com, cl@os.amperecomputing.com, linux-xfs@vger.kernel.org, Zi Yan Subject: Re: [PATCH v8 06/10] iomap: fix iomap_dio_zero() for fs bs > system page size Message-ID: <20240702120250.GA17373@lst.de> References: <20240625114420.719014-1-kernel@pankajraghav.com> <20240625114420.719014-7-kernel@pankajraghav.com> <20240702074203.GA29410@lst.de> <20240702101556.jdi5anyr3v5zngnv@quentin> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240702101556.jdi5anyr3v5zngnv@quentin> User-Agent: Mutt/1.5.17 (2007-11-01) X-Rspamd-Queue-Id: 0AD81180020 X-Stat-Signature: k55woaawwmrxymxtkruzecytiii6454o X-Rspamd-Server: rspam09 X-Rspam-User: X-HE-Tag: 1719921775-672797 X-HE-Meta: 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 oV8Ks3Yb Yoh/kirZLuqGcs1RzPpf4zTHHUriKdISvPUMkeuPhN3dQQ59wpdy9NMfgvtlLvo9LJR+gX0FJfufvJ0g26ahdoISJiCicNNWqn9d/tGOvIIa7/JIHLb0kBlflvw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Jul 02, 2024 at 10:15:56AM +0000, Pankaj Raghav (Samsung) wrote: > Willy suggested we could use raw pages as we don't need the metadata > from using a folio. [0] Ok, that feels weird but I'll defer to his opinion in that case. > > > + /* > > > + * Max block size supported is 64k > > > + */ > > > + WARN_ON_ONCE(len > ZERO_PAGE_64K_SIZE); > > > > > > A WARN_ON without actually erroring out here is highly dangerous. > > I agree but I think we decided that we are safe with 64k for now as fs > that uses iomap will not have a block size > 64k. > > But this function needs some changes when we decide to go beyond 64k > by returning error instead of not returning anything. > Until then WARN_ON_ONCE would be a good stop gap for people developing > the feature to go beyond 64k block size[1]. Sure, but please make it return an error and return that instead of just warning and going beyond the allocated page.