From owner-freebsd-fs@freebsd.org  Mon Dec 25 17:25:19 2017
Return-Path: <owner-freebsd-fs@freebsd.org>
Delivered-To: freebsd-fs@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id 6E219E9A72F
 for <freebsd-fs@mailman.ysv.freebsd.org>; Mon, 25 Dec 2017 17:25:19 +0000 (UTC)
 (envelope-from mi+thun@aldan.algebra.com)
Received: from symbion.zaytman.com (inet-64-112-176-10.bos.netblazr.com
 [64.112.176.10])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client CN "symbion", Issuer "Narawntapu" (not verified))
 by mx1.freebsd.org (Postfix) with ESMTPS id 2E8D46BC42
 for <freebsd-fs@freebsd.org>; Mon, 25 Dec 2017 17:25:18 +0000 (UTC)
 (envelope-from mi+thun@aldan.algebra.com)
Received: from narawntapu.narawntapu
 (pool-108-53-87-28.nwrknj.fios.verizon.net [108.53.87.28])
 by symbion.zaytman.com (8.15.2/8.15.2) with ESMTPS id vBPHPBLU003352
 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK)
 for <freebsd-fs@freebsd.org>; Mon, 25 Dec 2017 12:25:11 -0500 (EST)
 (envelope-from mi+thun@aldan.algebra.com)
X-Authentication-Warning: symbion.zaytman.com: Host
 pool-108-53-87-28.nwrknj.fios.verizon.net [108.53.87.28] claimed to be
 narawntapu.narawntapu
Received: from aldan.narawntapu (aldan [192.168.1.10])
 by narawntapu.narawntapu (8.15.2/8.15.2) with ESMTP id vBPHP96m059829
 for <freebsd-fs@freebsd.org>; Mon, 25 Dec 2017 12:25:09 -0500 (EST)
 (envelope-from mi+thun@aldan.algebra.com)
X-Authentication-Warning: narawntapu.narawntapu: Host aldan [192.168.1.10]
 claimed to be aldan.narawntapu
To: freebsd-fs <freebsd-fs@freebsd.org>
From: "Mikhail T." <mi+thun@aldan.algebra.com>
Subject: kqueue/kevent - watching an entire filesystem?
Message-ID: <9795fa64-b2dc-50c3-c7e0-8422e0388c15@aldan.algebra.com>
Date: Mon, 25 Dec 2017 12:25:09 -0500
MIME-Version: 1.0
Content-Language: en-US
X-DCC-dmv.com-Metrics: narawntapu 1095; Body=1 Fuz1=1 Fuz2=1
X-Spam-Status: No, score=-2.9 required=7.5 tests=ALL_TRUSTED,BAYES_00,
 HTML_MESSAGE autolearn=ham autolearn_force=no version=3.4.1
X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on
 narawntapu.narawntapu
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
X-Content-Filtered-By: Mailman/MimeDel 2.1.25
X-BeenThere: freebsd-fs@freebsd.org
X-Mailman-Version: 2.1.25
Precedence: list
List-Id: Filesystems <freebsd-fs.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-fs>,
 <mailto:freebsd-fs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-fs/>
List-Post: <mailto:freebsd-fs@freebsd.org>
List-Help: <mailto:freebsd-fs-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
 <mailto:freebsd-fs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 25 Dec 2017 17:25:19 -0000

It looks like an watching an arbitrary sub-tree with kqueue remains out 
of reach on FreeBSD -- one needs to traverse the entire (sub)tree first 
and create a separate kevent for each subdirectory.

But, maybe, watching an entire filesystem for changes can be 
accomplished easier? If not just any filesystem -- a ZFS one?

Thanks!

    -mi