[Lustre-discuss] Patchless client support for lustre 1.4.11

[Bernd Schubert]

Hello Ashok,

On Tuesday 29 April 2008 08:52:52 ashok bharat bayana wrote:
> Hello all!
>
> My project requires to work with lustre 1.4.11(both client(patchless
> client) and server). But I came to know that patchless client support is
> not there for luistre 1.4.11.  My task here is to make lustre 1.4.11 client
> give  patchless client support.for this I hav to go through the lustre 1.6
> source code(as 1.6 has patchless client support) and figure out the
> differences between the two and make 1.4.11 to support patchless clients. I
> dont know how to proceed in this aspect.
>
> I need help.Its urgent.

I don't understand what you are planning to do and actually I wouldn't bother 
to create a patchless client. Lustre-1.6 clients are compatible with 
lustre-1.4 servers.

Regarding the patchless server support, I don't know, adjusting the server 
side patches for specific kernel version is rather easy, since these patches 
are rather straightforward. Don't know if it worth the trouble to create 
patchless support.

Regarding the client side patches, this might become a bit tricky. In 
lustre-1.4 the "struct nameidata" (linux/namei.h) was patched to include 
additional intent fields (afaik linux-2.4 even didn't have this strucure).
All vfs functions using struct nameidata now had been patched to initialize 
the additional fields (vfs_intent-*.patch and vfs_nointent*.patch).
Also, I think these additional fields had been used only for nfs, cifs and 
lustre itself. 
Its was also around lustre-1.6.2 (so already some months ago) when I last 
looked how lustre-1.6 is doing it, but as far as I remember, lustre 1.6 now 
copies all fields of struct nameidata into a structure very close to the old 
patched struct nameidata. 

Hope it helps a bit. (And please note, I'm not a lustre developer, but we 
usually need more recent kernels than sun/clusterfs officially supports). 
Maybe also helpful for you, you may find lustre-1.4.11 with support for 
linux-2.6.20 here: 
http://www.pci.uni-heidelberg.de/tc/usr/bernd/downloads/lustre/1.4/lustre-1.4.11-ql2.tar.bz


Cheers,
Bernd


-- 
Bernd Schubert
Q-Leap Networks GmbH