Nothing is written to /dev/zram? in kernel 2.6.37-rc5

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What steps will reproduce the problem?
1.follow the README: modprobe, set size, mkswap, swapon 
2.swapon reports "swapon: /dev/zram0: read swap header failed: Invalid argument"
3.also tried: mkfs.btrfs, which succedes OK, but mount says "mount: you must 
specify the filesystem type"
4.tried to "dd" first 512 bytes and look at them, all I see are zero-es.

What version of the product are you using? On what operating system?
zram provided by kernel 2.6.37-rc5 (OpenSUSE HEAD)

Please provide any additional information below.
Seems that nothing is written to /dev/zram? devices.
This is my first try at zram, until today I was using ramzswap 0.6.2, compiled 
it for almost all -RC kernels since 2.6.35 and used without problems.

Original issue reported on code.google.com by sinisa.bandin on 18 Dec 2010 at 5:21

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Hi,
same here. It seems the version in 2.6.37 is broken. Filing a kernel bug: 
https://bugzilla.kernel.org/show_bug.cgi?id=25722

Original comment by D.G.Jan...@gmail.com on 27 Dec 2010 at 3:05

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Hi, can you please test the patch Nitin posted here?
https://lkml.org/lkml/2010/12/27/155

Original comment by D.G.Jan...@gmail.com on 30 Dec 2010 at 8:53

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Fixed in mainline:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=e983
dc2428164698571e1dd1b25c4322181adbac

Original comment by nitingupta910@gmail.com on 30 Dec 2010 at 10:39

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Hmmm, weird, I just started seeing this error for the first time after 
upgrading from 3.8 => 3.9.

However the swap does appear to ultimately activate, because "free" reports 
that it is there.

Original comment by jeremy.w...@gmail.com on 25 Jun 2013 at 2:52

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