Re: [PATCH] nfs: fix nfs4d readlink truncated packet

[Avi Kivity <avi@cloudius-systems.com>]

On 06/26/2014 05:23 PM, Avi Kivity wrote:
> XDR requires 4-byte alignment; nfs4d READLINK reply writes out the padding,
> but truncates the packet to the padding-less size.
>
> Fix by taking the padding into consideration when truncating the packet.
>

Ping.  I should have mentioned that without this, readlink() returns an 
I/O error on the client.

> Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
> ---
>   fs/nfsd/nfs4xdr.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
> index 83baf2b..cba93ea 100644
> --- a/fs/nfsd/nfs4xdr.c
> +++ b/fs/nfsd/nfs4xdr.c
> @@ -3267,7 +3267,7 @@ nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd
>   
>   	wire_count = htonl(maxcount);
>   	write_bytes_to_xdr_buf(xdr->buf, length_offset, &wire_count, 4);
> -	xdr_truncate_encode(xdr, length_offset + 4 + maxcount);
> +	xdr_truncate_encode(xdr, length_offset + 4 + ALIGN(maxcount, 4));
>   	if (maxcount & 3)
>   		write_bytes_to_xdr_buf(xdr->buf, length_offset + 4 + maxcount,
>   						&zero, 4 - (maxcount&3));