NFSv4: Fix a regression against the FreeBSD server

Technically, the Linux client is allowed by the NFSv4 spec to send
3 word bitmaps as part of an OPEN request. However, this causes the
current FreeBSD server to return NFS4ERR_ATTRNOTSUPP errors.

Fix the regression by making the Linux client use a 2 word bitmap unless
doing NFSv4.2 with labeled NFS.

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

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 0abfb8466e796cb8c0894ae6fbc38180865904f4..c74d6168db99b917ad202c874a9f161f29e920e5 100644 (file)
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -999,6 +999,7 @@ static void encode_attrs(struct xdr_stream *xdr, const struct iattr *iap,
        __be32 *p;
        __be32 *q;
        int len;
+       uint32_t bmval_len = 2;
        uint32_t bmval0 = 0;
        uint32_t bmval1 = 0;
        uint32_t bmval2 = 0;
@@ -1010,7 +1011,7 @@ static void encode_attrs(struct xdr_stream *xdr, const struct iattr *iap,
         * = 40 bytes, plus any contribution from variable-length fields
         *            such as owner/group.
         */
-       len = 20;
+       len = 8;
 
        /* Sigh */
        if (iap->ia_valid & ATTR_SIZE)
@@ -1040,8 +1041,6 @@ static void encode_attrs(struct xdr_stream *xdr, const struct iattr *iap,
                }
                len += 4 + (XDR_QUADLEN(owner_grouplen) << 2);
        }
-       if (label)
-               len += 4 + 4 + 4 + (XDR_QUADLEN(label->len) << 2);
        if (iap->ia_valid & ATTR_ATIME_SET)
                len += 16;
        else if (iap->ia_valid & ATTR_ATIME)
@@ -1050,15 +1049,22 @@ static void encode_attrs(struct xdr_stream *xdr, const struct iattr *iap,
                len += 16;
        else if (iap->ia_valid & ATTR_MTIME)
                len += 4;
+       if (label) {
+               len += 4 + 4 + 4 + (XDR_QUADLEN(label->len) << 2);
+               bmval_len = 3;
+       }
+
+       len += bmval_len << 2;
        p = reserve_space(xdr, len);
 
        /*
         * We write the bitmap length now, but leave the bitmap and the attribute
         * buffer length to be backfilled at the end of this routine.
         */
-       *p++ = cpu_to_be32(3);
+       *p++ = cpu_to_be32(bmval_len);
        q = p;
-       p += 4;
+       /* Skip bitmap entries + attrlen */
+       p += bmval_len + 1;
 
        if (iap->ia_valid & ATTR_SIZE) {
                bmval0 |= FATTR4_WORD0_SIZE;
@@ -1112,10 +1118,11 @@ static void encode_attrs(struct xdr_stream *xdr, const struct iattr *iap,
                                len, ((char *)p - (char *)q) + 4);
                BUG();
        }
-       len = (char *)p - (char *)q - 16;
+       len = (char *)p - (char *)q - (bmval_len << 2);
        *q++ = htonl(bmval0);
        *q++ = htonl(bmval1);
-       *q++ = htonl(bmval2);
+       if (bmval_len == 3)
+               *q++ = htonl(bmval2);
        *q = htonl(len);
 
 /* out: */