Commit 24abdf1b authored by Chuck Lever's avatar Chuck Lever Committed by Anna Schumaker

xprtrdma: Fix Read chunk padding

When pad optimization is disabled, rpcrdma_convert_iovs still
does not add explicit XDR round-up padding to a Read chunk.

Commit 677eb17e ("xprtrdma: Fix XDR tail buffer marshalling")
incorrectly short-circuited the test for whether round-up padding
is needed that appears later in rpcrdma_convert_iovs.

However, if this is indeed a regular Read chunk (and not a
Position-Zero Read chunk), the tail iovec _always_ contains the
chunk's padding, and never anything else.

So, it's easy to just skip the tail when padding optimization is
enabled, and add the tail in a subsequent Read chunk segment, if
disabled.

Fixes: 677eb17e ("xprtrdma: Fix XDR tail buffer marshalling")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 26ae102f
......@@ -226,8 +226,10 @@ rpcrdma_convert_iovs(struct xdr_buf *xdrbuf, unsigned int pos,
if (len && n == RPCRDMA_MAX_SEGS)
goto out_overflow;
/* When encoding the read list, the tail is always sent inline */
if (type == rpcrdma_readch)
/* When encoding a Read chunk, the tail iovec contains an
* XDR pad and may be omitted.
*/
if (type == rpcrdma_readch && xprt_rdma_pad_optimize)
return n;
/* When encoding the Write list, some servers need to see an extra
......@@ -238,10 +240,6 @@ rpcrdma_convert_iovs(struct xdr_buf *xdrbuf, unsigned int pos,
return n;
if (xdrbuf->tail[0].iov_len) {
/* the rpcrdma protocol allows us to omit any trailing
* xdr pad bytes, saving the server an RDMA operation. */
if (xdrbuf->tail[0].iov_len < 4 && xprt_rdma_pad_optimize)
return n;
n = rpcrdma_convert_kvec(&xdrbuf->tail[0], seg, n);
if (n == RPCRDMA_MAX_SEGS)
goto out_overflow;
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment