Re: [PATCH] make cramfs look less hostile

[Andries Brouwer]

On Sun, Jun 15, 2003 at 07:18:53PM +0100, Christoph Hellwig wrote:
> On Sun, Jun 15, 2003 at 08:14:24PM +0200, Jörn Engel wrote:
> > Yes, I agree.  It is any the "Cramfs didn't find it's magic number,
> > now we'll try another filesystem instead.
> 
> The only places where this should happen is mounting the rootfs.
> mount(8) has it's own filesystem type detection code and doesn't
> call mount(2) unless it found a matching filesystem type.

Too optimistic a description.
Any person who likes reliable results will give mount a -t option.
If someone likes to gamble, and doesnt mind system crashes, he'll
omit the -t and let mount guess what the type should have been.
Mount has a battery of heuristics for a handful of filesystems.
If any of these succeeds mount will try that type.
If none succeeds, mount will try consecutively all types listed
in /proc/filesystems for which no heuristic is present.

(Reality is more complicated, but the above is a good first
approximation.)

Andries