[2.6.0-test1-mm2] unable to mount root fs on unknown-block(0,0)

[2.6.0-test1-mm2] unable to mount root fs on unknown-block(0,0)

[Florian Huber]

Hello ML,
I can't boot my 2.6.0-test1-mm2 kernel (+GCC 3.3). The kernel panics
at bootime:

VFS: Cannot open root device "hda3" or unknow-block(0,0)
Please append a correct "root=" boot option
Kernel Panic: VFS: Unable to mount root fs on unknown-block(0,0)

I do have compiled support for the file system on my root partition
(xfs). The same configuration worked well with 2.6.0-test1-mm1.

Perhaps somebody knows how to solve this.

TIA
	Florian Huber

Re: [2.6.0-test1-mm2] unable to mount root fs on unknown-block(0,0)

[Felipe Alfaro Solana]

On Sun, 2003-07-20 at 12:55, Florian Huber wrote:
> Hello ML,
> I can't boot my 2.6.0-test1-mm2 kernel (+GCC 3.3). The kernel panics
> at bootime:
> 
> VFS: Cannot open root device "hda3" or unknow-block(0,0)
> Please append a correct "root=" boot option
> Kernel Panic: VFS: Unable to mount root fs on unknown-block(0,0)
> 
> I do have compiled support for the file system on my root partition
> (xfs). The same configuration worked well with 2.6.0-test1-mm1.
> 
> Perhaps somebody knows how to solve this.

I've also seen this when trying to boot -mm2. Every configuration option
was left as it was in -mm1. Andrew, any ideas?

Re: [2.6.0-test1-mm2] unable to mount root fs on unknown-block(0,0)

[Joe]

Felipe Alfaro Solana wrote:

>On Sun, 2003-07-20 at 12:55, Florian Huber wrote:
>  
>
>>Hello ML,
>>I can't boot my 2.6.0-test1-mm2 kernel (+GCC 3.3). The kernel panics
>>at bootime:
>>
>>VFS: Cannot open root device "hda3" or unknow-block(0,0)
>>Please append a correct "root=" boot option
>>Kernel Panic: VFS: Unable to mount root fs on unknown-block(0,0)
>>
>>I do have compiled support for the file system on my root partition
>>(xfs). The same configuration worked well with 2.6.0-test1-mm1.
>>
>>Perhaps somebody knows how to solve this.
>>    
>>
>
>I've also seen this when trying to boot -mm2. Every configuration option
>was left as it was in -mm1. Andrew, any ideas?
>  
>
FWIW, I have the same problem with -mm2, -mm1 was fine, same config.

Joe

Re: [2.6.0-test1-mm2] unable to mount root fs on unknown-block(0,0)

[Jeremy Fitzhardinge]

On Sun, 2003-07-20 at 03:55, Florian Huber wrote:
> Hello ML,
> I can't boot my 2.6.0-test1-mm2 kernel (+GCC 3.3). The kernel panics
> at bootime:
> 
> VFS: Cannot open root device "hda3" or unknown-block(0,0)
> Please append a correct "root=" boot option
> Kernel Panic: VFS: Unable to mount root fs on unknown-block(0,0)

I'm getting the same thing, with an ext3 root.  It seems that something
odd is happening in init/do_mounts.c, since from the message it looks
like ROOT_DEV isn't being initialized.  However the mm2 patch doesn't
seem to change anything significant-looking in this directory (just some
headers).  

Hm, on closer inspection, it resolves the device name by mounting sysfs,
rummaging around to see if the device exists and gets its device number
(0301 for hda1) and initializes ROOT_DEV from that.  I wonder if there's
a sysfs/block device breakage which makes the partitions not appear in
sysfs?  Setting root=0303 (in your case) might helps things along.

	J

Re: [2.6.0-test1-mm2] unable to mount root fs on unknown-block(0,0)

[Jeremy Fitzhardinge]

On Sun, 2003-07-20 at 14:54, Jeremy Fitzhardinge wrote: 
>  Setting root=0303 (in your case) might helps things along.

root=0302 works for me, but root=/dev/hda2 and root=hda2 both fail, even
though /sys/block/hda/hda2/dev contains good values.

Hm, looks like try_path() in init/do_mounts.c generates paths which
don't exist.  If you specify root=/dev/hda2, try_paths will look in 
/sys/block/hda2/dev, but it needs to be /sys/block/hda/hda2/dev.  I
tried playing with it a bit, but then it started trying to mount from
hda4 for no obvious reason...

But this should be enough to go on with.

	J

Re: [2.6.0-test1-mm2] unable to mount root fs on unknown-block(0,0)

[Florian Huber]

On 20 Jul 2003 14:54:52 -0700
Jeremy Fitzhardinge <jeremy@goop.org> wrote:

> Setting root=0303 (in your case) might helps things along.

Thanks Jeremy, it's working :)

Re: [2.6.0-test1-mm2] unable to mount root fs on unknown-block(0,0)

[Christian Axelsson]

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On Mon, 2003-07-21 at 17:38, Florian Huber wrote:
> On 20 Jul 2003 14:54:52 -0700
> Jeremy Fitzhardinge <jeremy@goop.org> wrote:
> 
> > Setting root=0303 (in your case) might helps things along.
> 
> Thanks Jeremy, it's working :)

Yea this helps (I use root=0301 for /dev/hda1) but is the reason behind
this behavior located and fixed?

-- 
Christian Axelsson
  smiler@lanil.mine.nu

GPG ID:
  6C3C55D9 @ ldap://keyserver.pgp.com

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[PATCH 2.6.0-test1-mm2] fix unable to mount root fs

[Daniel McNeil]

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The problem is being caused by the dev_t changes that now print out
dev_t's as major:minor instead of a hex value.  See print_dev_t().

This patch changes try_name() in init/do_mounts.c to get the major
and minor and return a MKDEV(major, minor).  I've tested this on
my machines and it boots with root=/dev/hda2.

Daniel McNeil <daniel@osdl.org>
On Sun, 2003-07-20 at 03:55, Florian Huber wrote:
> Hello ML,
> I can't boot my 2.6.0-test1-mm2 kernel (+GCC 3.3). The kernel panics
> at bootime:
> 
> VFS: Cannot open root device "hda3" or unknow-block(0,0)
> Please append a correct "root=" boot option
> Kernel Panic: VFS: Unable to mount root fs on unknown-block(0,0)
> 
> I do have compiled support for the file system on my root partition
> (xfs). The same configuration worked well with 2.6.0-test1-mm1.
> 
> Perhaps somebody knows how to solve this.
> 
> TIA
> 	Florian Huber
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[-- Attachment #2: patch.2.6.0-test1-mm2.do_mounts --]
[-- Type: text/x-patch, Size: 922 bytes --]

diff -rupN -X /home/daniel_nfs/dontdiff linux-2.6.0-test1-mm2/init/do_mounts.c linux-2.6.0-test1-mm2.do_mounts/init/do_mounts.c
--- linux-2.6.0-test1-mm2/init/do_mounts.c	2003-07-23 11:19:32.018914859 -0700
+++ linux-2.6.0-test1-mm2.do_mounts/init/do_mounts.c	2003-07-23 11:25:19.356002570 -0700
@@ -58,6 +58,7 @@ static dev_t __init try_name(char *name,
 	char *s;
 	int len;
 	int fd;
+	unsigned int maj, min;
 
 	/* read device number from .../dev */
 
@@ -70,8 +71,12 @@ static dev_t __init try_name(char *name,
 	if (len <= 0 || len == 32 || buf[len - 1] != '\n')
 		goto fail;
 	buf[len - 1] = '\0';
-	res = (dev_t) simple_strtoul(buf, &s, 16);
-	if (*s)
+	/*
+	 * The format of dev is now %u:%u -- see print_dev_t()
+	 */
+	if (sscanf(buf, "%u:%u", &maj, &min) == 2)
+		res = MKDEV(maj, min);
+	else
 		goto fail;
 
 	/* if it's there and we are not looking for a partition - that's it */