From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Lameter <clameter@sgi.com>
Subject: Re: [11/36] Use page_cache_xxx in fs/buffer.c
Date: Thu, 30 Aug 2007 18:47:45 -0700 (PDT)
Message-ID: <Pine.LNX.4.64.0708301843280.13292@schroedinger.engr.sgi.com>
References: <20070828190551.415127746@sgi.com> <20070828190730.220393749@sgi.com>
 <20070830092038.GD22586@dnb.sw.ru> <Pine.LNX.4.64.0708301113170.7975@schroedinger.engr.sgi.com>
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Cc: torvalds@linux-foundation.org, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
	Mel Gorman <mel@skynet.ie>,
	William Lee Irwin III <wli@holomorphy.com>,
	David Chinner <dgc@sgi.com>,
	Jens Axboe <jens.axboe@oracle.com>,
	Badari Pulavarty <pbadari@gmail.com>,
	Maxim Levitsky <maximlevitsky@gmail.com>,
	Fengguang Wu <fengguang.wu@gmail.com>,
	swin wang <wangswin@gmail.com>, totty.lu@gmail.com,
	"H. Peter Anvin" <hpa@zytor.com>, joern@lazybastard.org,
	"Eric W. Biederman" <ebiederm@xmission.com>
To: Dmitry Monakhov <dmonakhov@sw.ru>
Return-path: <linux-kernel-owner+glk-linux-kernel-3=40m.gmane.org-S1763824AbXHaBsF@vger.kernel.org>
In-Reply-To: <Pine.LNX.4.64.0708301113170.7975@schroedinger.engr.sgi.com>
Sender: linux-kernel-owner@vger.kernel.org
List-Id: linux-fsdevel.vger.kernel.org

This may already be handled?

submit_bh() calls submit_bio() which calls __generic_make_request() and 
there we do:

                if (unlikely(bio_sectors(bio) > q->max_hw_sectors)) {
                        printk("bio too big device %s (%u > %u)\n",
                                bdevname(bio->bi_bdev, b),
                                bio_sectors(bio),
                                q->max_hw_sectors);
                        goto end_io;
                }

So if we try to push a too large buffer down with submit_bh() we get a 
failure.