Re: [PATCH v2] NFSv4: fix getacl ERANGE for some ACL buffer sizes

[Weston Andros Adamson <dros@netapp.com>]

On Dec 10, 2013, at 2:19 PM, Trond Myklebust <trond.myklebust@primarydata.com> wrote:

> 
> On Dec 10, 2013, at 21:11, Weston Andros Adamson <dros@netapp.com> wrote:
> 
>> 
>> On Dec 10, 2013, at 1:13 PM, Trond Myklebust <trond.myklebust@primarydata.com> wrote:
>> 
>>> On Thu, 2013-11-21 at 16:20 -0500, Weston Andros Adamson wrote:
>> 
>>> 
>>>> 	if (res.acl_scratch)
>>>> diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
>>>> index 5be2868..4e2e2da 100644
>>>> --- a/fs/nfs/nfs4xdr.c
>>>> +++ b/fs/nfs/nfs4xdr.c
>>>> @@ -5207,8 +5207,6 @@ static int decode_getacl(struct xdr_stream *xdr, struct rpc_rqst *req,
>>>> 	if ((status = decode_op_hdr(xdr, OP_GETATTR)) != 0)
>>>> 		goto out;
>>>> 
>>>> -	xdr_enter_page(xdr, xdr->buf->page_len);
>>> 
>>> Why is this being removed?
>> 
>> Because it BUG()s! ;)
>> 
>> I must admit that I don’t get why xdr_enter_page() doesn’t work when the XDR layer does the page allocation, but it does not — and the nfs3xdr ACL code (which uses the XDR layer allocation) also doesn’t call this.  It worked well without this, so I just removed it and didn’t investigate why.
> 
> I’m guessing that xdr->buf>page_len is being set incorrectly by the code that does the page allocation and/or that it is failing to update xdr->buf->len and/or xdr->buf->buflen.
> 
> We really do need the xdr_enter_page() here, or the acl bitmap + data won’t be aligned properly on the page boundary.

Ok, I’ll add that back and then fix the oops… and investigate if the v3 ACL code needs it too…

Thanks,
-dros