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Date:   Mon, 23 Aug 2021 08:57:00 +0800
From:   Wang Yugui <wangyugui@e16-tech.com>
To:     Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Subject: Re: [PATCH] VFS/BTRFS/NFSD: provide more unique inode number for btrfs export
Cc:     NeilBrown <neilb@suse.de>, Christoph Hellwig <hch@infradead.org>,
        Josef Bacik <josef@toxicpanda.com>,
        "J. Bruce Fields" <bfields@fieldses.org>,
        Chuck Lever <chuck.lever@oracle.com>, Chris Mason <clm@fb.com>,
        David Sterba <dsterba@suse.com>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org,
        linux-btrfs@vger.kernel.org
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References: <162932318266.9892.13600254282844823374@noble.neil.brown.name> <20210819021910.GB29026@hungrycats.org>
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Hi,

> rsync -H and cpio's hardlink detection can be badly confused.  They will
> think distinct files with the same inode number are hardlinks.  This could
> be bad if you were making backups (though if you're making backups over
> NFS, you are probably doing something that could be done better in a
> different way).

'rysnc -x ' and 'find -mount/-xdev' will fail to work in
snapper config?
snapper is a very important user case.

Although  yet not some option like '-mount/-xdev' for '/bin/cp',
but maybe come soon.

I though the first patchset( crossmnt in nfs client) is the right way,
because in most case, subvol is a filesystem, not  a directory.

Best Regards
Wang Yugui (wangyugui@e16-tech.com)
2021/08/23