Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752049Ab2K2Gat (ORCPT ); Thu, 29 Nov 2012 01:30:49 -0500 Received: from zeniv.linux.org.uk ([195.92.253.2]:55066 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751100Ab2K2Gas (ORCPT ); Thu, 29 Nov 2012 01:30:48 -0500 Date: Thu, 29 Nov 2012 06:30:43 +0000 From: Al Viro To: Linus Torvalds Cc: Mikulas Patocka , Jens Axboe , Jeff Chua , Lai Jiangshan , Jan Kara , lkml , linux-fsdevel Subject: Re: [PATCH] Introduce a method to catch mmap_region (was: Recent kernel "mount" slow) Message-ID: <20121129063043.GJ4939@ZenIV.linux.org.uk> References: <20121129062519.GI4939@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121129062519.GI4939@ZenIV.linux.org.uk> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 707 Lines: 14 On Thu, Nov 29, 2012 at 06:25:19AM +0000, Al Viro wrote: > Umm... set_blocksize() is calling kill_bdev(), which does > truncate_inode_pages(mapping, 0). What's going to happen to data in > the dirty pages? IO in progress is not the only thing to worry about... Note that sync_blockdev() a few lines prior to that is good only if we have no other processes doing write(2) (or dirtying the mmapped pages, for that matter). The window isn't too wide, but... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/