From mboxrd@z Thu Jan 1 00:00:00 1970 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 smtp.subspace.kernel.org (Postfix) with ESMTPS id 1EDBE1EBA1C; Tue, 4 Mar 2025 23:40:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741131602; cv=none; b=Y2mXYTMKgxba3dQGeClxQw0v/0UJXlM4HUOzpb4CZErUBHO+kEeUWM3Rj9N2OEmduMQWJv7aGOo1W90C81BB9Ku/5Q8yCm1MsZeyf1w7hFYbg5N6yKoo+yk96G+EIhA+5fzJ9Ix8/exENjVODWMfnmGIBH/3m37yBwXgxB70LzA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741131602; c=relaxed/simple; bh=QZVDvEFUU0e/0iB+w5j1DnY0DCmhWxMFhb8RsVzuLUs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GFxuoE7KwFmLTpquiFbeNrikrKcxw6O9V7Gs4EuEkitvB31oLAe0RjK+P+sAtSrYlEqPMEVXVFQWdEw3aF3y0gwgTlWTg7VbRl/xMiC36MJXYKQ4VwVFyKuV1/GONEr9XZwlrXIbky8zxA9y1p+2BrVh0F8KG8EYBvD8zPGP9dI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=NE73DCj+; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="NE73DCj+" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=+m1aYezl8/hAr3njLk/YkPvClWtmRrt93Sm/63bNujo=; b=NE73DCj+tA4WV+jlcWBBANUV1e /nHUcvDbtn3lDh52EQt6y+osJ+7ipVXNmHhMeWnQibNsS0o+Af5HRlOO3z55XosCneuKhHulhv5bj tyAV77UhTBBv3Dc7hyY0WEdE8oohkySQQnCJJPImEuytCKEXwRiy4/B+djAarIO0UMqsrrYCiROjE 232Bf2I4nHMmej7LZIhEYNR6yKzpg+6lbZItAAPku94qKqXRdywWRB65hC1jZ0bRnkB5K+sx3+pa6 5MyA0ThBeCna9NAXvNBevUDlXnCxgD9yHxTDHP7ob6Cy0zApqDIZE9ez/sGEh2L7ENEQvi5VxtGfi 72QSZ0Mg==; Received: from hch by bombadil.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1tpbrk-00000006XnH-1jgA; Tue, 04 Mar 2025 23:40:00 +0000 Date: Tue, 4 Mar 2025 15:40:00 -0800 From: Christoph Hellwig To: Pavel Begunkov Cc: Dave Chinner , Christian Brauner , linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, "Darrick J . Wong" , linux-xfs@vger.kernel.org, wu lei Subject: Re: [PATCH v2 1/1] iomap: propagate nowait to block layer Message-ID: References: <970ec89d-4161-41f4-b66f-c65ebd4bd583@gmail.com> Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <970ec89d-4161-41f4-b66f-c65ebd4bd583@gmail.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Tue, Mar 04, 2025 at 10:47:48PM +0000, Pavel Begunkov wrote: > Are you only concerned about the size being too restrictive or do you > see any other problems? You can't know the size beforehand. A stacking block driver can split the I/O for absolutely any reason it wants, and there is no requirement to propagate that up to the queue limits. That's why we need to be able to synchronously return the wouldblock error to get this right.