NFSv4: Replace callback string decode function with a generic

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

1 files changed, 8 insertions, 22 deletions

diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
index e732a65db546..2ade5cb52b8e 100644
--- a/fs/nfs/callback_xdr.c
+++ b/fs/nfs/callback_xdr.c
@@ -83,23 +83,15 @@ static __be32 *read_buf(struct xdr_stream *xdr, size_t nbytes)
         return p;
 }
 
-static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len, const char **str)
+static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len,
+                const char **str, size_t maxlen)
 {
-        __be32 *p;
-
-        p = read_buf(xdr, 4);
-        if (unlikely(p == NULL))
-                return htonl(NFS4ERR_RESOURCE);
-        *len = ntohl(*p);
-
-        if (*len != 0) {
-                p = read_buf(xdr, *len);
-                if (unlikely(p == NULL))
-                        return htonl(NFS4ERR_RESOURCE);
-                *str = (const char *)p;
-        } else
-                *str = NULL;
+        ssize_t err;
 
+        err = xdr_stream_decode_opaque_inline(xdr, (void **)str, maxlen);
+        if (err < 0)
+                return cpu_to_be32(NFS4ERR_RESOURCE);
+        *len = err;
         return 0;
 }
 
@@ -162,15 +154,9 @@ static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound
         __be32 *p;
         __be32 status;
 
-        status = decode_string(xdr, &hdr->taglen, &hdr->tag);
+        status = decode_string(xdr, &hdr->taglen, &hdr->tag, CB_OP_TAGLEN_MAXSZ);
         if (unlikely(status != 0))
                 return status;
-        /* We do not like overly long tags! */
-        if (hdr->taglen > CB_OP_TAGLEN_MAXSZ) {
-                printk("NFS: NFSv4 CALLBACK %s: client sent tag of length %u\n",
-                                __func__, hdr->taglen);
-                return htonl(NFS4ERR_RESOURCE);
-        }
         p = read_buf(xdr, 12);
         if (unlikely(p == NULL))
                 return htonl(NFS4ERR_RESOURCE);