kinit problem with cciss root device

kinit problem with cciss root device

[Bjorn Helgaas]

kinit converts "root=/dev/cciss/c0d0p1" to "cciss.c0d0", which
doesn't exist under /sys/block because register_disk() converts
"cciss/c0d0" to "cciss!c0d0" (note "!", not ".").

I don't know whether it's the *right* fix, but the patch below
makes things work.  It still doesn't make kinit exactly match
the register_disk() behavior because register_disk() only changes
the first "/" in the string.

This was a nuisance to debug because when it failed, the only
output I got was this:

  ...
  Adding console on ttyS0 at I/O port 0x3f8 (options '115200')
  Time: tsc clocksource has been installed.
  Freeing unused kernel memory: 260k freed
    argc == 4
  Kernel panic - not syncing: Attempted to kill init!
    argv[0]: "/ini 

So you might consider something like the "drain output" hunk below,
which allowed all the useful messages to get out.


Index: work-mm8/usr/kinit/kinit.c
===================================================================
--- work-mm8.orig/usr/kinit/kinit.c	2006-06-05 19:04:46.000000000 -0600
+++ work-mm8/usr/kinit/kinit.c	2006-06-06 14:19:59.000000000 -0600
@@ -317,5 +317,10 @@
 	if (mnt_sysfs)
 		umount2("/sys", 0);
 
+	/*
+	 * Allow time for messages to drain before kernel panics
+	 * because init is exiting.
+	 * */
+	sleep(10);
 	exit(ret);
 }
Index: work-mm8/usr/kinit/name_to_dev.c
===================================================================
--- work-mm8.orig/usr/kinit/name_to_dev.c	2006-06-05 19:04:46.000000000 -0600
+++ work-mm8/usr/kinit/name_to_dev.c	2006-06-06 14:19:02.000000000 -0600
@@ -151,7 +151,7 @@
 
 	for (p = s; *p; p++)
 		if (*p == '/')
-			*p = '.';
+			*p = '!';
 	res = try_name(s, 0);
 	if (res)
 		return res;

Re: kinit problem with cciss root device

[H. Peter Anvin]

Bjorn Helgaas wrote:
> 
> So you might consider something like the "drain output" hunk below,
> which allowed all the useful messages to get out.
> 

Hm.  That's rather ugly.  Anyone knows if TCFLSB works on /dev/console?

> 
> Index: work-mm8/usr/kinit/kinit.c
> ===================================================================
> --- work-mm8.orig/usr/kinit/kinit.c	2006-06-05 19:04:46.000000000 -0600
> +++ work-mm8/usr/kinit/kinit.c	2006-06-06 14:19:59.000000000 -0600
> @@ -317,5 +317,10 @@
>  	if (mnt_sysfs)
>  		umount2("/sys", 0);
>  
> +	/*
> +	 * Allow time for messages to drain before kernel panics
> +	 * because init is exiting.
> +	 * */
> +	sleep(10);
>  	exit(ret);
>  }

	-hpa

Re: kinit problem with cciss root device

[H. Peter Anvin]

H. Peter Anvin wrote:
> Bjorn Helgaas wrote:
>>
>> So you might consider something like the "drain output" hunk below,
>> which allowed all the useful messages to get out.
>>
> 
> Hm.  That's rather ugly.  Anyone knows if TCFLSB works on /dev/console?
> 

That should of course have been TCSBRK(1), as in tcdrain().

	-hpa

Re: kinit problem with cciss root device

[H. Peter Anvin]

Bjorn Helgaas wrote:
> kinit converts "root=/dev/cciss/c0d0p1" to "cciss.c0d0", which
> doesn't exist under /sys/block because register_disk() converts
> "cciss/c0d0" to "cciss!c0d0" (note "!", not ".").
> 
> I don't know whether it's the *right* fix, but the patch below
> makes things work.  It still doesn't make kinit exactly match
> the register_disk() behavior because register_disk() only changes
> the first "/" in the string.
> 

That's still the right thing; obviously register_disk() will need to change if we ever 
have deeper trees.

Could you re-send that hunk as a proper patch with Signed-off-by: et al?

Thanks,

	-hpa