re: NFSv4: Fix a regression against the FreeBSD server

[Dan Carpenter <dan.carpenter@oracle.com>]

Hello Trond Myklebust,

This is a semi-automatic email about new static checker warnings.

The patch b4a2cf76ab7c: "NFSv4: Fix a regression against the FreeBSD 
server" from Jul 17, 2013, leads to the following Smatch complaint:

fs/nfs/nfs4xdr.c:1103 encode_attrs()
	 error: we previously assumed 'label' could be null (see line 1059)

fs/nfs/nfs4xdr.c
  1058		}
  1059		if (label) {
                    ^^^^^
New check.

  1060			len += 4 + 4 + 4 + (XDR_QUADLEN(label->len) << 2);
  1061			bmval[2] |= FATTR4_WORD2_SECURITY_LABEL;
  1062		}
  1063	
  1064		if (bmval[2] != 0)
  1065			bmval_len = 3;
  1066		else if (bmval[1] != 0)
  1067			bmval_len = 2;
  1068		else
  1069			bmval_len = 1;
  1070	

[snip]

  1094		if (bmval[1] & FATTR4_WORD1_TIME_MODIFY_SET) {
  1095			if (iap->ia_valid & ATTR_MTIME_SET) {
  1096				*p++ = cpu_to_be32(NFS4_SET_TO_CLIENT_TIME);
  1097				p = xdr_encode_hyper(p, (s64)iap->ia_mtime.tv_sec);
  1098				*p++ = cpu_to_be32(iap->ia_mtime.tv_nsec);
  1099			} else
  1100				*p++ = cpu_to_be32(NFS4_SET_TO_SERVER_TIME);
  1101		}
  1102		if (bmval[2] & FATTR4_WORD2_SECURITY_LABEL) {
  1103			*p++ = cpu_to_be32(label->lfs);
                                           ^^^^^^^^^^
Old dereference.

  1104			*p++ = cpu_to_be32(label->pi);
  1105			*p++ = cpu_to_be32(label->len);

regards,
dan carpenter