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Date:   Thu, 29 Nov 2018 12:11:29 +0900
From:   Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To:     Dave Rodgman <dave.rodgman@arm.com>
Cc:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        nd <nd@arm.com>,
        "herbert@gondor.apana.org.au" <herbert@gondor.apana.org.au>,
        "davem@davemloft.net" <davem@davemloft.net>,
        Matt Sealey <Matt.Sealey@arm.com>,
        "nitingupta910@gmail.com" <nitingupta910@gmail.com>,
        "rpurdie@openedhand.com" <rpurdie@openedhand.com>,
        "markus@oberhumer.com" <markus@oberhumer.com>,
        "minchan@kernel.org" <minchan@kernel.org>,
        "sonnyrao@google.com" <sonnyrao@google.com>,
        "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        "akpm@linux-foundation.org" <akpm@linux-foundation.org>,
        Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Subject: Re: [PATCH 6/7] lib/lzo: implement run-length encoding
Message-ID: <20181129031129.GG6379@jagdpanzerIV>
References: <20181127161913.23863-1-dave.rodgman@arm.com>
 <20181127161913.23863-7-dave.rodgman@arm.com>
 <20181129030840.GF6379@jagdpanzerIV>
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On (11/29/18 12:08), Sergey Senozhatsky wrote:
> On (11/27/18 16:19), Dave Rodgman wrote:
> >
> > This modifies the bitstream in a way which is backwards compatible
> > (i.e., we can decompress old bitstreams, but old versions of lzo
> > cannot decompress new bitstreams).
> >
> 
> Hmmm... Whoa. Help me understand this:
> 
> So a btrfs filesystem, compressed with the new lzo, say I run 4.21,
> won't be readable at all once I reboot under 4.19?
> 
> What about compressed net traffic between servers running different
> kernel version (one with new lzo, the other one with old lzo)?
> XFRM can be compressed with lzo, can't it?

Ah, false alarm. Sorry for the noise!

You create a new lzo version in the next patch.

	-ss