SUNRPC: Add xdr_pad_size() helper

Introduce a helper function to compute the XDR pad size of a
variable-length XDR object.

Clean up: Replace open-coded calculation of XDR pad sizes.
I'm sure I haven't found every instance of this calculation.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This commit is contained in:
Chuck Lever 2020-03-02 15:01:08 -05:00
parent 758a3bf945
commit 96f194b715
4 changed files with 21 additions and 10 deletions

View File

@ -300,6 +300,21 @@ xdr_align_size(size_t n)
return (n + mask) & ~mask;
}
/**
* xdr_pad_size - Calculate size of an object's pad
* @n: Size of an object being XDR encoded (in bytes)
*
* This implementation avoids the need for conditional
* branches or modulo division.
*
* Return value:
* Size (in bytes) of the needed XDR pad
*/
static inline size_t xdr_pad_size(size_t n)
{
return xdr_align_size(n) - n;
}
/**
* xdr_stream_encode_u32 - Encode a 32-bit integer
* @xdr: pointer to xdr_stream

View File

@ -1877,7 +1877,7 @@ static int gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
else
iov = snd_buf->head;
p = iov->iov_base + iov->iov_len;
pad = 3 - ((snd_buf->len - offset - 1) & 3);
pad = xdr_pad_size(snd_buf->len - offset);
memset(p, 0, pad);
iov->iov_len += pad;
snd_buf->len += pad;

View File

@ -961,7 +961,7 @@ unwrap_priv_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gs
/* XXX: This is very inefficient. It would be better to either do
* this while we encrypt, or maybe in the receive code, if we can peak
* ahead and work out the service and mechanism there. */
offset = buf->head[0].iov_len % 4;
offset = xdr_pad_size(buf->head[0].iov_len);
if (offset) {
buf->buflen = RPCSVC_MAXPAYLOAD;
xdr_shift_buf(buf, offset);
@ -1680,7 +1680,8 @@ svcauth_gss_wrap_resp_integ(struct svc_rqst *rqstp)
goto out;
integ_offset = (u8 *)(p + 1) - (u8 *)resbuf->head[0].iov_base;
integ_len = resbuf->len - integ_offset;
BUG_ON(integ_len % 4);
if (integ_len & 3)
goto out;
*p++ = htonl(integ_len);
*p++ = htonl(gc->gc_seq);
if (xdr_buf_subsegment(resbuf, &integ_buf, integ_offset, integ_len)) {

View File

@ -322,11 +322,6 @@ int svc_rdma_send(struct svcxprt_rdma *rdma, struct ib_send_wr *wr)
return ret;
}
static u32 xdr_padsize(u32 len)
{
return (len & 3) ? (4 - (len & 3)) : 0;
}
/* Returns length of transport header, in bytes.
*/
static unsigned int svc_rdma_reply_hdr_len(__be32 *rdma_resp)
@ -595,7 +590,7 @@ static int svc_rdma_pull_up_reply_msg(struct svcxprt_rdma *rdma,
if (wr_lst) {
u32 xdrpad;
xdrpad = xdr_padsize(xdr->page_len);
xdrpad = xdr_pad_size(xdr->page_len);
if (taillen && xdrpad) {
tailbase += xdrpad;
taillen -= xdrpad;
@ -670,7 +665,7 @@ int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma,
if (wr_lst) {
base = xdr->tail[0].iov_base;
len = xdr->tail[0].iov_len;
xdr_pad = xdr_padsize(xdr->page_len);
xdr_pad = xdr_pad_size(xdr->page_len);
if (len && xdr_pad) {
base += xdr_pad;