Re: [PATCH 3/4] NFSD: Add WRITE_PLUS support for hole punches

[Anna Schumaker <bjschuma@netapp.com>]

On Tue 29 Oct 2013 09:23:19 AM EDT, Myklebust, Trond wrote:
>
> On Oct 29, 2013, at 9:06 AM, J. Bruce Fields <bfields@fieldses.org> wrote:
>
>> On Tue, Oct 29, 2013 at 08:50:56AM -0400, Anna Schumaker wrote:
>>> On Mon 28 Oct 2013 05:40:30 PM EDT, J. Bruce Fields wrote:
>>>> On Mon, Oct 28, 2013 at 10:57:25AM -0400, Anna Schumaker wrote:
>>>>> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
>>>>> index 419572f..3210c6f 100644
>>>>> --- a/fs/nfsd/nfs4proc.c
>>>>> +++ b/fs/nfsd/nfs4proc.c
>>>>> @@ -1028,6 +1028,42 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
>>>>> 	return status;
>>>>> }
>>>>>
>>>>> +static __be32
>>>>> +nfsd4_write_plus_hole(struct file *file, struct nfsd4_write_plus *writeplus,
>>>>> +		      struct net *net)
>>>>> +{
>>>>> +	__be32 status;
>>>>> +
>>>>> +	status = nfsd4_vfs_fallocate(file, writeplus->wp_allocated,
>>>>> +				writeplus->wp_offset, writeplus->wp_length);
>>>>> +	if (status == nfs_ok) {
>>>>> +		writeplus->wp_res.wr_stid = NULL;
>>>>> +		writeplus->wp_res.wr_bytes_written = writeplus->wp_length;
>>>>> +		writeplus->wp_res.wr_stable_how = NFS_FILE_SYNC;
>>>>
>>>> Do we need to sync?
>>>
>>> I did the sync in nfsd4_vfs_fallocate (below), but I can move it if
>>> that would make more sense.
>>
>> What I meant was--why are we doing a sync at all, instead of returning
>> NFS_UNSTABLE and making the client commit?
>
> What if the client specifies FILE_SYNC? The spec doesn't allow the server to return UNSTABLE in that situation.

I don't have that check in there either, but I do think it would be 
useful if the client were prepared to handle an UNSTABLE reply from the 
server...

>
> Trond