Re: [V9fs-developer] Unable to load modules from 9p filesystem withkmod 16

From: Wakko Warner
Date: Sat Jan 11 2014 - 09:12:37 EST


Dominique Martinet wrote:
> Hi,

Hi.

The following was trimmed.

> > On 01/10/2014 03:03 PM, Wakko Warner wrote:
> > > Wakko Warner wrote:
> > >> Kernel 3.12.7 from kernel.org
> > >> With kmod-16, I'm unable to load any modules on my guest kvm machines.

> > >> open("/lib/modules/3.12.7/kernel/crypto/af_alg.ko", O_RDONLY|O_CLOEXEC) = 3
> > >> fstat(3, {st_mode=S_IFREG|0644, st_size=13822, ...}) = 0
> > >> mmap(NULL, 13822, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f199aebd000
> > >> syscall_313(0x3, 0x7f199aaa2de0, 0, 0x3, 0, 0x7f199b7b2010, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) = -1 (errno 8)
> > >> munmap(0x7f199aebd000, 13822) = 0
> > >> close(3) = 0
>
> I didn't look at the patch very closely because the mail apparently
> never reached v9fs-developer (although it looks in copy), but I got
> pointed out this patch recently:
> http://www.spinics.net/lists/linux-virtualization/msg21716.html

I applied the patch on that page. Here's my result:

# df -T /lib/modules/3.12.7/kernel
Filesystem Type 1K-blocks Used Available Use% Mounted on
kernel 9p 2015056 721356 1172460 39% /kernel
# uname -r
3.12.7
# modprobe -V
kmod version 16
# lsmod
Module Size Used by
nfsd 217278 2
auth_rpcgss 41307 1 nfsd
oid_registry 2179 1 auth_rpcgss
exportfs 3499 1 nfsd
nfs 111109 0
...

> Which quotes "This patch enables 9p-virtio to correctly handle this
> case. This not only enables us to load Linux kernel modules off virtfs,"
>
> Perhaps would it be what you need to support this syscall_313?

Looks like that's the fix.

--
Microsoft has beaten Volkswagen's world record. Volkswagen only created 22
million bugs.
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