[pnfs] CVS: nfsv4

[Iyer, Rahul]

Hi,
I mean the inode freeing routines, not the free_layout () call. Here's
the problem...
The xdr encode routine takes the inode as part of the arguments. It uses
this to get the file handle for the PUTFH in the compound containing the
LAYOUTRETURN. I agree, we could get the file handle earlier and then
pass this down instead of the inode.

But the other problem is that we need the rpc_clnt struct too. This is
also present in the inode. We could extract this also, but we wind up in
a race with umount. During umount, the rpc_shutdown_clients kills all
outstanding rpc_clnt structs. 

So, here's my plan. I plan to make ir sort of async, but not exactly. I
will issue the rpc asynchronously, but wait for it to complete. While
this is not truly asynchronous, it avoids the races we have. It however,
is slightly better than synchronous because the user can now interrupt
it. 

Thanks
Regards
Rahul


-----Original Message-----
From: Marc Eshel [mailto:eshel at almaden.ibm.com] 
Sent: Tuesday, August 01, 2006 9:20 AM
To: Iyer, Rahul
Cc: Rahul Iyer (NetApp); pnfs at linux-nfs.org
Subject: RE: [pnfs] CVS: nfsv4

What exactly is the problem? Can't you remove the pointer current_layout
from the inode (set it to NULL) and than you can either free it even
before the async call or if you need it for some reason free it in
rpc_call_done ? 
I think that this call should be async.
Marc.

pnfs-bounces at linux-nfs.org wrote on 07/31/2006 10:29:22 PM:

> PFA the patch for the following commit. 
> Regards
> Rahul
> 
> 
> -----Original Message-----
> From: Rahul Iyer (NetApp) [mailto:iyer at citi.umich.edu]
> Sent: Monday, July 31, 2006 10:28 PM
> To: pnfs at linux-nfs.org
> Subject: [pnfs] CVS: nfsv4
> 
> CVSROOT:   /cvs
> Module name:   nfsv4
> Changes by:   iyer at citi.   2006/08/01 01:28:20
> 
> Modified files:
>    cvs/pnfs/fs/nfs: nfs4proc.c
> 
> Log message:
> Making LAYOUTRETURN synchronous. Having LAYOUTRETURN be asynchronous 
> causes race condition between LAYOUTRETURN and the inode freeing 
> routines.
> 
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> [attachment "diff" deleted by Marc Eshel/Almaden/IBM] 
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