Am 07.12.2010 14:30, schrieb Dieter Plaetinck:
The problem is: If blkid finds more than one valid signature, it will not return anything, and we will mistakenly believe that there is no file system (and happily overwrite the drive). This part of initscripts is giving me a headache everytime I touch it.
what do the util-linux-ng maintainers say about that? Isn't this something that should be fixed in the blkid source code?
No, that won't be fixed - at least not the way you think. Older blkid-like tools used to report the first matched signature. That resulted in (for example) using an ext3 file system that also happened to have a valid swap header as swapspace, destroying the ext3 file system. (There are tons of other examples like this, in particular, old versions of cryptsetup and mkswap didn't wipe old existing file system headers.) It was decided that blkid will refuse to report any ambiguous match as a match. I'm thinking about requesting a feature that allows to report any match, ambiguous or not.