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Cc: akpm@osdl.org, Evgeniy Polyakov <johnpol@2ka.mipt.ru>,
	Albert Cahalan <acahalan@gmail.com>, Greg KH <greg@kroah.com>,
	linux-kernel@vger.kernel.org, Ingo Oeser <ioe-lkml@rameria.de>,
	linux-mtd@lists.infradead.org, Jan Engelhardt <jengelh@linux01.gwdg.de>,
	linux-fsdevel@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>
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Jörn Engel wrote:
> Compressing random data will actually enlarge it.  If that happens I
> simply store the verbatim uncompressed data instead and mark it as such.
> 
> There is also demand for a user-controlled bit in the inode to disable
> compression completely.  All those .jpg, .mpg, .mp3, etc. just waste
> time by trying and failing to compress them.

So any sane way to enable compression is on per-inode basis which makes 
me still wonder why you need per-object compression.