[pnfs] Layoutreturn Implementation

[Dean Hildebrand]

Iyer, Rahul wrote:
> Yeah, probably true, but what if LAYOUTRETURN does fail? clear_inode()
> returns nothing (void clear_inode()), so there's no way to signal an
> error anyways! Besides, going  by the comment for the clear_inode()
> function...
> <snip>
> /**
>  * clear_inode - clear an inode
>  * @inode: inode to clear
>  *
>  * This is called by the filesystem to tell us
>  * that the inode is no longer useful. We just
>  * terminate it with extreme prejudice.
>  */
> void clear_inode(struct inode *inode)
> </snip>
>
> There's not much to be gained from being synchronous. It seems to me
> that doing a LAYOUTRETURN as a "best effort" seems reasonable...
> Regards
> Rahul
>   
If we don't care, then I would do it sync as it is the easiest and 
requires the least amount of code.
Dean
>
> -----Original Message-----
> From: Dean Hildebrand [mailto:dhildebz at eecs.umich.edu] 
> Sent: Thursday, July 20, 2006 1:52 PM
> To: Iyer, Rahul
> Cc: pnfs at linux-nfs.org
> Subject: Re: [pnfs] Layoutreturn Implementation
>
> I think it has to be sync since we can't remove the inode until it
> completes successfully.
> Dean
>
> Iyer, Rahul wrote:
>   
>> Hi,
>> Currently, free_layout() is being called from only one functioon: 
>> nfs4_clear_inode(). nfs4_clear_inode() is the .clear_inode pointer of 
>> super_operations. The .clear_inode pointer is called by clear_inode().
>> This is called mainly to remove the in memory inode reference.
>>  
>> The function that I spoke about, wwhich makes the LAYOUTRETURN rpc is 
>> pnfs_return_layout(). This function is, however called nowhere. All 
>> that needs to be done on the client is to call pnfs_return_layout() in
>>     
>
>   
>> nfs4_clear_inode().
>> So, I presume it's fairly simple. However, I had a question:
>> nfs4_proc_pnfs_layoutreturn() makes a call to rpc_call_sync(). Should 
>> LAYOUTRETURN be a synchronous RPC? Is it better asynchronous? Do we
>>     
> care?
>   
>>  
>> Thanks
>> Rahul
>>  
>>  
>> ----------------------------------------------------------------------
>> --
>>
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>>     
>
> --
> Dean Hildebrand
> Ph.D. Candidate
> University of Michigan
>   

-- 
Dean Hildebrand
Ph.D. Candidate
University of Michigan