NFSv4: Don't use private xdr_stream fields in decode_getacl

Instead of using the private field xdr->p from struct xdr_stream,
use the public xdr_stream_pos().

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 6 insertions, 5 deletions

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 54d3f5a9faa6..1bfbd67c556d 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -5045,10 +5045,10 @@ static int decode_getacl(struct xdr_stream *xdr, struct rpc_rqst *req,
                          struct nfs_getaclres *res)
 {
         unsigned int savep;
-        __be32 *bm_p;
         uint32_t attrlen,
                  bitmap[3] = {0};
         int status;
+        unsigned int pg_offset;
 
         res->acl_len = 0;
         if ((status = decode_op_hdr(xdr, OP_GETATTR)) != 0)
@@ -5056,7 +5056,8 @@ static int decode_getacl(struct xdr_stream *xdr, struct rpc_rqst *req,
 
         xdr_enter_page(xdr, xdr->buf->page_len);
 
-        bm_p = xdr->p;
+        /* Calculate the offset of the page data */
+        pg_offset = xdr->buf->head[0].iov_len;
 
         if ((status = decode_attr_bitmap(xdr, bitmap)) != 0)
                 goto out;
@@ -5070,18 +5071,18 @@ static int decode_getacl(struct xdr_stream *xdr, struct rpc_rqst *req,
                 /* The bitmap (xdr len + bitmaps) and the attr xdr len words
                  * are stored with the acl data to handle the problem of
                  * variable length bitmaps.*/
-                res->acl_data_offset = (xdr->p - bm_p) << 2;
+                res->acl_data_offset = xdr_stream_pos(xdr) - pg_offset;
 
                 /* We ignore &savep and don't do consistency checks on
                  * the attr length.  Let userspace figure it out.... */
                 res->acl_len = attrlen;
-                if (attrlen + res->acl_data_offset > xdr->buf->page_len) {
+                if (attrlen > (xdr->nwords << 2)) {
                         if (res->acl_flags & NFS4_ACL_LEN_REQUEST) {
                                 /* getxattr interface called with a NULL buf */
                                 goto out;
                         }
                         dprintk("NFS: acl reply: attrlen %u > page_len %u\n",
-                                        attrlen, xdr->buf->page_len);
+                                        attrlen, xdr->nwords << 2);
                         return -EINVAL;
                 }
         } else