Re: [Qemu-devel] [V9fs-developer] QEMU dies on any attempt to load a Linux kernel module when using a 9P rootfs

[Christopher Covington <cov@codeaurora.org>]

Hi Dominique,

On 08/22/2014 02:27 AM, Dominique Martinet wrote:
> Hi,
> 
> Christopher Covington wrote on Thu, Aug 21, 2014 at 03:50:58PM -0400:
>> With my 3.15.0+ kernel, qemu-system-x86_64 substituted for qemu-kvm, and the
>> path changed from your arguments I get:
>>
>> 9pnet_virtio: no channels available
>> VFS: Cannot open root device "root" or unknown-block(0,0): error -2
>> Please append a correct "root=" boot option; here are the available partitions:
>> 0b00         1048575 sr0  driver: sr
>> Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
>> rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
> 
> I'm pretty sure that's the same problem that's been reported a few times
> here, could you try again after cherry-picking this commit:
> 
> commit f15844e0777fec936f87a87f97394f83911dacd3
> Author: Dominique Martinet <dominique.martinet@cea.fr>
> Date:   Wed May 21 10:02:12 2014 +0200
> 
>     9P: fix return value in v9fs_fid_xattr_set
>     
>     v9fs_fid_xattr_set is supposed to return 0 on success.
>     
>     This corrects the behaviour introduced in commit
>     bdd5c28dcb8330b9074404cc92a0b83aae5606a
>     "9p: fix return value in case in v9fs_fid_xattr_set()"
>     
>     (The function returns a negative error on error, as expected)
>     
>     Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
>     Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
> 
> 
> It has gotten in in v3.16-rc1, so your 3.15.0+ proably doesn't have it.

Thanks for the pointer to this patch. I think I started this kernel half way
through the 3.16 merge window. The last non-cherry-picked patch I have is:

commit 6d87c225f5d82d29243dc124f1ffcbb0e14ec358
Merge: 338c09a 22001f6
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Thu Jun 12 23:06:23 2014 -0700

    Merge branch 'for-linus' of
git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client

So I do have the change you pointed out. Nevertheless, I'll reconfirm with the
latest torvalds/master.

Thanks,
Christopher

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