From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 13D095464E for ; Fri, 14 Feb 2025 01:37:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739497054; cv=none; b=X6Jyn+G+DbOrzLC8YtjG/SPwESD7uoR+jhMYYCHzX4NN4gOFFV+6wep1gYxnVjf7WGWHbUQZ0frYWKMcUB0i05xIr+c1rNraO/VTliURV3V7est20pjj3V5C+Rn1KdtyO1QsOx9CWMu/fucI11zNESNJIpzbBD4hITKFOA1Nr6o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739497054; c=relaxed/simple; bh=th2a3/NR4yque+I+XMypzM08WC3VfGK3QaeeVf4/ZJA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ak+9Hi7rHFdCpujbaRSo8MudnerALXz7dg+jjn9bZuYUhn7k+5dBuyjrU4Dcx23nAFo631bJEDNhgdYprwZ3aFfeHKhIvVfAiMxZAgQSj5Iif6lK/ueL0akNwn0Y9/O1lN4MZKmTo1YRBvfGarTtt41VBJCX7MFX76hbvhrhHs4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=TDWyiB43; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="TDWyiB43" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1739497052; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=PLsi2bsHcAnbAizdWk411TmzIEVW5qW0GKyRVefphv0=; b=TDWyiB43KFivN75nSHyWZAyfxtQVc1Dcsb+74r2NKlHPF34XNP/x43uzqmGPeH9rHZJVOi UG6Vx2fd4ligFgM63t1YzRjwJrG18X3/6oIJmNyylK3vPKUTP3UTi1sZ+zBg5NI0/0sm3o Z8WeqeYyPNSWVHCj9TTYF2M1/+2HcGU= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-629-Jw6paGdyO2-qKfB2yhYcSw-1; Thu, 13 Feb 2025 20:37:27 -0500 X-MC-Unique: Jw6paGdyO2-qKfB2yhYcSw-1 X-Mimecast-MFC-AGG-ID: Jw6paGdyO2-qKfB2yhYcSw Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 96AEC180034A; Fri, 14 Feb 2025 01:37:25 +0000 (UTC) Received: from fedora (unknown [10.72.120.24]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id F1025300018D; Fri, 14 Feb 2025 01:37:16 +0000 (UTC) Date: Fri, 14 Feb 2025 09:37:10 +0800 From: Ming Lei To: Daniel Gomez Cc: Christoph Hellwig , Luis Chamberlain , Jens Axboe , linux-block@vger.kernel.org, Yi Zhang , John Garry , Bart Van Assche , Keith Busch , Daniel Gomez Subject: Re: [PATCH V2] block: make segment size limit workable for > 4K PAGE_SIZE Message-ID: References: <20250210090319.1519778-1-ming.lei@redhat.com> Precedence: bulk X-Mailing-List: linux-block@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: X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 On Thu, Feb 13, 2025 at 03:18:43PM +0100, Daniel Gomez wrote: > On Thu, Feb 13, 2025 at 04:51:55PM +0100, Ming Lei wrote: > > On Thu, Feb 13, 2025 at 12:30:29AM -0800, Christoph Hellwig wrote: > > > On Thu, Feb 13, 2025 at 04:02:46PM +0800, Ming Lei wrote: > > > > The problem[1] is that this kind of mmc card fails to be recognized as > > > > block disk. Block layer io split code can handle this case actually. > > > > > > When we still had bio_add_pc_page it would break the assumption that > > > you could always add a full page. With that gone and everything going > > > through the split machinery we might be fine now, but backporting it > > > to 6.13 and earlier will cause breakage. > > > > Yes, I will mention the following two are depended for backporting in > > commit log: > > > > 02ee5d69e3ba block: remove blk_rq_bio_prep > > 6aeb4f836480 block: remove bio_add_pc_page > > Ming, is that sufficient for your use case? Or do you still need to remove the > assumption that the "minimum" segment size is not PAGE_SIZE? If you want to make any block device with < 64K max_segment_size working on 64K page_size kernel, you need this patch and the following three dependencies: commit 6aeb4f836480 ("block: remove bio_add_pc_page") commit 02ee5d69e3ba ("block: remove blk_rq_bio_prep") commit b7175e24d6ac ("block: add a dma mapping iterator") Thanks, Ming