[Toybox] filesystem note and test images

[Rob Landley]

On 10/09/2013 10:25:51 AM, Conroy, Bradley Quentin wrote:
> I posted my filesystem notes to a google docs spreadsheet at:
> https://docs.google.com/spreadsheet/ccc?key=0Aj5C85KHF6xBdDRBaDZSMWVZZGg4NWFDM0F3SFRlR0E&usp=sharing
> Anyone feel free to edit if your favorite filesystem is  
> missing/wrong.  I have exhausted
> my set of test images at this point.

I was rather hoping to get the test images so I could test _my_ code  
against them. Mountable ones, ideally.

This list is... odd. You have sysfs in here, tmpfs, sockfs... These are  
not block backed filesystem. These tools operate on block devices...

> You can grep -aob to find the offset of a known string (useful for  
> utf8 labels)
> many of the magics are strings too, for instance squash's 0x73717368  
> becomes
> "hsqs" (translate 2 bytes at a time backwards)

Yes, there's often comments to that effect in the kernel soruce which  
is what I was using for this. At mount-time the drivers verify that  
this _is_ an instance of said filesystem, and those are the tests I was  
replicating.

> I have also attached a tarball of some compressed images that I used  
> for testing.

Yay! Now that is useful to me. Mind if I include it in the test suite?

Um... wow. 128 meg f2fs image? Almost half a gig total for the  
directory?

Remember when I said you could "bzcat image.bz2 | blkid -" ? I think  
the test suite's going to be doing a lot of that... :)

Rob