lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

RPC/RDMA: adhere to protocol for unpadded client trailing write chunks.

Browse Source 
The RPC/RDMA protocol allows clients and servers to avoid RDMA
operations for data which is purely the result of XDR padding.
On the client, automatically insert the necessary padding for
such server replies, and optionally don't marshal such chunks.

Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Tom Talpey
2008-10-09 15:01:11 -04:00
committed by Trond Myklebust
parent fee08caf94
commit 9191ca3b38
3 changed files with 33 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
net/sunrpc/xprtrdma/rpc_rdma.c
View File

@@ -118,6 +118,10 @@ rpcrdma_convert_iovs(struct xdr_buf *xdrbuf, unsigned int pos,
}
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;
if (n == nsegs)
return 0;
seg[n].mr_page = NULL;
@@ -594,7 +598,7 @@ rpcrdma_count_chunks(struct rpcrdma_rep *rep, unsigned int max, int wrchunk, __b
* Scatter inline received data back into provided iov's.
*/
static void
rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len)
rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len, int pad)
{
int i, npages, curlen, olen;
char *destp;
@@ -660,6 +664,13 @@ rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len)
} else
rqst->rq_rcv_buf.tail[0].iov_len = 0;
if (pad) {
/* implicit padding on terminal chunk */
unsigned char *p = rqst->rq_rcv_buf.tail[0].iov_base;
while (pad--)
p[rqst->rq_rcv_buf.tail[0].iov_len++] = 0;
}
if (copy_len)
dprintk("RPC: %s: %d bytes in"
" %d extra segments (%d lost)\n",
@@ -794,14 +805,20 @@ repost:
((unsigned char *)iptr - (unsigned char *)headerp);
status = rep->rr_len + rdmalen;
r_xprt->rx_stats.total_rdma_reply += rdmalen;
/* special case - last chunk may omit padding */
if (rdmalen &= 3) {
rdmalen = 4 - rdmalen;
status += rdmalen;
}
} else {
/* else ordinary inline */
rdmalen = 0;
iptr = (__be32 *)((unsigned char *)headerp + 28);
rep->rr_len -= 28; /*sizeof *headerp;*/
status = rep->rr_len;
}
/* Fix up the rpc results for upper layer */
rpcrdma_inline_fixup(rqst, (char *)iptr, rep->rr_len);
rpcrdma_inline_fixup(rqst, (char *)iptr, rep->rr_len, rdmalen);
break;
case __constant_htonl(RDMA_NOMSG):