From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([59.151.112.132]:28775 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751129AbbAFINI convert rfc822-to-8bit (ORCPT ); Tue, 6 Jan 2015 03:13:08 -0500 Message-ID: <54AB990E.4070101@cn.fujitsu.com> Date: Tue, 6 Jan 2015 16:13:02 +0800 From: Qu Wenruo MIME-Version: 1.0 To: Lennart Poettering , Subject: Re: RFE: per-subvolume timestamp that is updated on every change to a subvolume References: <20150105172754.GC19126@gardel-login> <54AB7A5A.10408@cn.fujitsu.com> In-Reply-To: <54AB7A5A.10408@cn.fujitsu.com> Content-Type: text/plain; charset="utf-8"; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: -------- Original Message -------- Subject: Re: RFE: per-subvolume timestamp that is updated on every change to a subvolume From: Qu Wenruo To: Lennart Poettering , Date: 2015年01月06日 14:02 > > -------- Original Message -------- > Subject: RFE: per-subvolume timestamp that is updated on every change > to a subvolume > From: Lennart Poettering > To: > Date: 2015年01月06日 01:27 >> Heya! >> >> I am looking for a nice way to query the overall last modification >> timestamp of a subvolume. i.e. the most recent mtime of *any* file or >> directory within a subvolume. Ideally, I think, there was a >> btrfs_timespec field for this in "struct btrfs_root_item", alas there >> isn't afaics. Any chance this can be added? > In fact, btrfs_root_item contains one btrfs_inode_item, which contains > the a/c/m/otime. > But not sure if it contains the time you need. > > I'd better add acmotime output for inode_item in btrfs-debug-tree and > try myself. > > Thanks, > Qu The value in acmotime of the inode_item in root_item is not used, so it seems anyone can use it to record the acmotime for your purpose. Thanks, Qu >> >> Or is there another workable way to query this value? Maybe determine >> it from the current generation of a subvolume or so? Is that tracked? >> Ideas? >> >> Lennart >> -- >> To unsubscribe from this list: send the line "unsubscribe >> linux-btrfs" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html