squashfs 2.2 and backward compatibility

  • mirakels

    Hi Philip,
    I just noticed you released squashfs 2.2 containing the fix/workarounds for the small memory systems (like the dreambox). Thanks!

    I wonder however, are these and the other changes transparent to older squashfs versions? E.g. can this new version read filesystems created with older squashfs versions, and can older squashfs versions read filesystems created with this new release?



    • Yes.  I was a bit rushed in posting 2.2, and so the help-me etc. was rather brief.  I wanted to get the new release out before I started my new company today.  My previous company (I worked there two months) claimed ownership of all work performed in my spare time, and so I couldn't do any work on SquashFS (otherwise the company would have owned it).  Happily my new company doesn't make such claims, but I wanted a new release as soon as possible after leaving my last company, and preferably before I started the company I'm now working for!

      The current release (2.2) is completely compatible with release 2.1.  The current Mksquashfs generates filesystems mountable with release 2.1, and (same as release 2.1), with the -2.0 flag, it will generate filesystems mountable with any release from 2.0-ALPHA.  The current release can mount any SquashFS filesystem  from SquashFS 1.0 onwards.  This is irrespective of whether the constrained memory options are selected or not (fragment cache of 1, and Vmalloc rather than Kmalloc).