Re: waiting 10s before mounting root filesystem?

[Marcelo Tosatti <marcelo.tosatti@cyclades.com>]

On Fri, Dec 31, 2004 at 11:26:34AM +0000, Paulo Marques wrote:
> Andrew Morton wrote:
> >William Park <opengeometry@yahoo.ca> 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.