[OLPC-devel] Re: Won't boot from unclean file system (trac 55)

[David Woodhouse]

On Sat, 2006-08-26 at 08:58 -0400, Jim Gettys wrote:
> So you are suggesting we have a /boot partition with ext2 for the disk
> image to solve the LinuxBIOS problem?  But why won't the payload Linux
> image allow us to mount the file system in the first place, despite the
> unclean dismount?  It is not as if the kernel image could possibly have
> been written and be unclean itself, and the boot sequence itself will
> run fsck and clean the root file system at boot time.

It's not about being unclean. It's about being _incompatible_. 

Ext3 and ext2 are compatible only by coincidence. And only when there's
_nothing_ outstanding in the journal. When there are writes outstanding
in the journal, they are _not_ compatible.

I don't know precisely why -- perhaps this is just someone being overly
paranoid and you could get away with just making the LinuxBIOS ext2
_pretend_ that it handles filesystems with the "dirty journal"
compatibility flag set. But I would assume that the flag was made an
"incompatible" flag instead of a "read only" flag for a reason.

-- 
dwmw2