Re: [E2FSPROGS, RFC] New mke2fs types parsing

[Theodore Tso <tytso@MIT.EDU>]

On Tue, Mar 18, 2008 at 08:11:32AM -0500, Eric Sandeen wrote:
> Theodore Tso wrote:
> 
> > I rejected this approach originally because it would mean reusing the
> > -t option right away.  But maybe this would be easier for users to
> > understand, and easier to document in the man pages, and maybe that's
> > an overriding consideration.
> 
> well, I doubt the man page should override much ;)
> 
> I just wanted to air the concerns & my ideas... if, having considered
> them, you're still happy with the original approach, that's fine with me.

Sure, but making things easier to understand is important.  So we
trade off making "mke2fs -t" doing something different between 1.40
and 1.41, with something that might be easier to understand.

So what do people think about this proposal as an alternative to
what's been discussed?

The filesystem type comes from defaults.fstype in mke2fs.conf, which
can be overridden by /sbin/mkfs.*, which in turn can be overriden by
the -t option.  If the the filesystem type does not begin with the
string "ext" it will be rejected with an error.  Call this the
"fs_type".

In addition, a list of types can be specified by the user using the -T
flag.  Call it "type_list", and it consists of one or more usage types
separated by commas.  If a type_list is not specified by -T, mke2fs
use a single type based on the size of the block device, selected from
the list "floppy, small, default".

Mke2fs will search mke2fs.conf for configuration parameters first by
looking at the fs_type, and then successively in the usage types found
in type_list.  Parameters found later override earlier parameters.

I can get behind this, as it's compatible with what came before, and
simpler in the general case, and still as expressive for power users
who want to do really complex things in their mke2fs.conf file.

What do people think?

							- Ted