From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 0623E28CF77; Sat, 4 Jul 2026 04:38:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783139896; cv=none; b=m+yxxha2ZjlCaLS3/JPwJQ4cs8n+2ufD7vI3THEmshcQjP4EQTzLyy32pWvHkkzM1YTd+RXT0Mab2D6LRGzrBS0IsiKDXkcMEvTNHEJSP6DnGzIwco72kB0b5ULO854SH5u3Fw8GASSfeF9KtT50b2hGlQlILAz88xuXbkC4BdE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783139896; c=relaxed/simple; bh=yRJWIPYU7x9O4o82CkNjHV3Q+ojcQHdhKbof/8IUxkI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=AyhRY0e0tksHKei9UsszKPgE0ycNqZcf5OgxyZ19KwbpUqRaUE3/xZh4qWzKsUGJMcDAs8b8XiJyko9Z74noHoOTCNCkLTBj6LR3idUljpMRDjzA3FPLNdSN1CExdF1pPiyNs/IUNgW4qAFNcG6/LPNW6a5QeXfIh7r7lBfT9nI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DXfbiV6g; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DXfbiV6g" Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id F35141F000E9; Sat, 4 Jul 2026 04:38:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783139889; bh=qRAmcRU3owZQdAAKakvkU8W3SwpcXOWxnb6DylVdk9c=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=DXfbiV6gKXNj8Wvs9hw5qkDLynuSYspyuLQhy00fnh1MqDD/O1hx1PQASm1qyaIDy diUZyrCsQRk1bp93hnlAfbd1FTZT6khHhBvtenlfMxl0CuH6U/Na71wHsu9K0f4fZn UXwB4GH0XiZ3KdAAqrbQHIvWhTmfpjGsW7mj/f31qSQnQ9LH6XUGPKYrHNf5/AZVVw D2atEWFNjynMkgF0r00OkSjCntE8Wccsc9OXtF0Pb5Yo56hhKTK71daRZSpVB0zg4H BsP41jGwa8i/K0kfC9JXAKJ8h2da/qjBaWTXWEk9ZtRliYRbHiTK0ZNK85I5pw1YZv MkS/8BYN0ApjQ== Date: Fri, 3 Jul 2026 21:38:08 -0700 From: "Darrick J. Wong" To: Joanne Koong Cc: Christoph Hellwig , brauner@kernel.org, willy@infradead.org, hsiangkao@linux.alibaba.com, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, Jonathan Corbet , Shuah Khan , "open list:DOCUMENTATION" , open list Subject: Re: [PATCH v2 18/18] Documentation: iomap: update docs to reflect iomap_next model Message-ID: <20260704043808.GC9407@frogsfrogsfrogs> References: <20260701000949.1666714-1-joannelkoong@gmail.com> <20260701000949.1666714-19-joannelkoong@gmail.com> <20260702192658.GN9392@frogsfrogsfrogs> <20260703020020.GS9392@frogsfrogsfrogs> <20260703124331.GA26440@lst.de> <20260703161147.GB9407@frogsfrogsfrogs> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Fri, Jul 03, 2026 at 05:34:59PM -0700, Joanne Koong wrote: > On Fri, Jul 3, 2026 at 9:11 AM Darrick J. Wong wrote: > > > > On Fri, Jul 03, 2026 at 02:43:31PM +0200, Christoph Hellwig wrote: > > > On Thu, Jul 02, 2026 at 07:00:20PM -0700, Darrick J. Wong wrote: > > > > The ->begin method can still set iomap::private and the ->end method can > > > > dispose of it, right? Oh, wait, no, that doesn't work because you're > > > > talking about ->begin/->end passing something to the next ->begin. > > > > > > Should we move ->private from struct iomap to struct iomap_iter? > > > That'll deal with the constness and the fact that private data > > > really is a per-operation thing. > > I'm not sure I understand. Doesn't struct iomap_iter already have a > private field that holds caller-supplied per-operation context? > afaics, the users of iomap->private (gfs2, ntfs3, fuse-dax) do use it > for per-mapping data and release it in the same iteration. Oh right, iomap_iter::private is a private pointer that the filesystem can sometimes set to pass per-file-operation data to ->iomap_{begin,end} ... that is tortuously extracted from the iomap_iter via the iomap pointer. iomap::private is a private pointer that the filesystem can set to pass per-mapping data from ->iomap_begin to ->iomap_end. IOWS, never mind, I'm babbling nonsense. --D > > I dunno -- towards the end of the fuse-iomap development work I actually > > had started using iomap.private to store per-mapping private data. But > > that work is dead now, so that's not a strong argument. > > > > > That also reminds me that now that we actually still keep the low-level > > > begin/end ops we need to switch them to a calling convention that > > > passes the iter instead of the ugly container_of. This is something > > > I wanted deferred until we get the iter conversion, but it turns out > > > that now leaves them untouched.. > > That's a good point. Do you think it'd be better to include those > changes as part of this series or do that as a separate follow-up > series that targets the same merge window timeline as this one? > > > > > Oh, you mean changing the signature to: > > > > typedef int (iomap_begin_fn)(struct iomap_iter *iter...); > > > > instead of passing parts of the iter as separate arguments? > > Yeah, that would be nice. > > Agreed. > > Thanks, > Joanne