Re: [2.5.51] Failure to mount ext3 root when ext2 compiled in

Andrew Morton
2002-12-13T04:02:10Z

Rusty Russell wrote:
>
> Just noticed this (usually ext2 is compiled as a module, but was
> testing a patch with CONFIG_MODULES=n). Reverted to plain 2.5.51, and
> it's still there:
>
> VFS: Cannot open root device "301" or 03:01
> Please append a correct "root=" boot option
> Kernel panic: VFS: Unable to mount root fs on 03:01
>
> Now, I have an ext3 root, but when CONFIG_EXT3_FS=y and
> CONFIG_EXT2_FS=y, I get this failure. Turning off CONFIG_EXT2_FS
> "fixes" it.
>

In the past year I've booted about 1,000,000,000 kernels with
CONFIG_EXT2_FS=y and CONFIG_EXT3_FS=y. Across that period,
maybe five or ten times I have seen this problem.

As soon as I get down to debug it it goes away. I once traced it
as far as seeing ext3_fill_super() return failure, then I lost it.

Rebuilding the kernel, even if you "didn't change anything" makes
it go away.

I assume that in your case a `make clean' will not fix it. You
lucky duck. Can you stick a printk right at the end of
ext3_fill_super()?