Re: waiting 10s before mounting root filesystem?

From: Marcelo Tosatti
Date: Fri Dec 31 2004 - 06:50:36 EST


On Fri, Dec 31, 2004 at 11:26:34AM +0000, Paulo Marques wrote:
> Andrew Morton wrote:
> >William Park <opengeometry@xxxxxxxx> wrote:
> >
> >>- printk("VFS: Cannot open root device \"%s\" or %s\n",
> >>- root_device_name, b);
> >>- printk("Please append a correct \"root=\" boot option\n");
> >>+ if (--tryagain) {
> >>+ printk (KERN_WARNING "VFS: Waiting %dsec for root
> >>device...\n", tryagain);
> >>+ ssleep (1);
> >>+ goto retry;
> >>+ }
> >>+ printk (KERN_CRIT "VFS: Cannot open root device \"%s\" or
> >>%s\n", root_device_name, b);
> >>+ printk (KERN_CRIT "Please append a correct \"root=\" boot
> >>option\n");
> >
> >
> >Why is this patch needed? If it is to offer the user a chance to insert
> >the correct medium or to connect the correct device, why not rely upon the
> >user doing that thing and then hitting reset?
>
> No, no. The problem is not user interaction.
>
> The problem is that the USB subsystem takes a lot of time to go through
> the hostcontrollers -> hubs -> devices. By the time it finds the USB
> mass storage that is supposed to be used as root filesystem, the kernel
> had already panic'ed.
>
> IMHO the kernel should handle this case just fine, without the need for
> initrd's. After all the user says "my root filesystem is /dev/sda1", and
> the kernel panic's even though the filesystem is there. This doesn't
> seem like a correct bahavior.

Well, Paulo's has more of a clue than I do.

Some CD drives suffer from the same issues.
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