Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751120AbaDUHZL (ORCPT ); Mon, 21 Apr 2014 03:25:11 -0400 Received: from mail-we0-f179.google.com ([74.125.82.179]:39821 "EHLO mail-we0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750712AbaDUHZJ (ORCPT ); Mon, 21 Apr 2014 03:25:09 -0400 MIME-Version: 1.0 In-Reply-To: References: <20140417212834.GC17769@csclub.uwaterloo.ca> From: Michael Kerrisk Date: Mon, 21 Apr 2014 09:24:47 +0200 X-Google-Sender-Auth: 5BdHoJ9UvD5rA7AkuIMFb__nX30 Message-ID: Subject: Re: inotify, new idea? To: Richard Weinberger Cc: Lennart Sorensen , Jos Huisken , Linux Kernel , Michael Kerrisk-manpages Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 21, 2014 at 12:22 AM, Richard Weinberger wrote: > On Fri, Apr 18, 2014 at 6:15 AM, Michael Kerrisk wrote: >> On Thu, Apr 17, 2014 at 11:28 PM, Lennart Sorensen >> wrote: >>> On Thu, Apr 17, 2014 at 11:00:37PM +0200, Jos Huisken wrote: >>>> I was trying to maintain a local and remote directory in sync with >>>> lsync, using inotify. >>>> I happen to have >4M files and >400k directories... running over >>>> /proc/sys/fs/inotify/max_user_watches >>> >>> Would fanotify perhaps be a better interface to use? >> >> (One of us is misunderstanding fanotify; it might be me.) >> >> Did you look at fanotify closely? I don't think it could be used for >> this task -- does not notify linka dn unlink events, difficult to set >> up recursive monitoring, etc. > > Does recursive monitoring even work with inotify? > Last time I've tried it did failed as soon I did a mkdir -p a/b/c/d because > mkdir() raced against the thread which installes the new watches. As I understand it, you have to program to deal with the races (rescan directories after adding watches). I recently did a lot of work updating the inotify(7) man page to discuss all the issues that I know of, and their remedies. If I missed anything, I'd appreciate a note on it, so that it can be added. See http://man7.org/linux/man-pages/man7/inotify.7.html#NOTES Cheers, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Author of "The Linux Programming Interface", http://blog.man7.org/ -- 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/