svcrpc: track rpc data length separately from sk_tcplen

Keep a separate field, sk_datalen, that tracks only the data contained
in a fragment, not including the fragment header.

For now, this is always just max(0, sk_tcplen - 4), but after we allow
multiple fragments sk_datalen will accumulate the total rpc data size
while sk_tcplen only tracks progress receiving the current fragment.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 12 insertions, 7 deletions

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 1db42b1ffe28..2b09e2306bfa 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -874,9 +874,9 @@ static unsigned int svc_tcp_restore_pages(struct svc_sock *svsk, struct svc_rqst
 {
         unsigned int i, len, npages;
 
-        if (svsk->sk_tcplen <= sizeof(rpc_fraghdr))
+        if (svsk->sk_datalen == 0)
                 return 0;
-        len = svsk->sk_tcplen - sizeof(rpc_fraghdr);
+        len = svsk->sk_datalen;
         npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
         for (i = 0; i < npages; i++) {
                 if (rqstp->rq_pages[i] != NULL)
@@ -893,9 +893,9 @@ static void svc_tcp_save_pages(struct svc_sock *svsk, struct svc_rqst *rqstp)
 {
         unsigned int i, len, npages;
 
-        if (svsk->sk_tcplen <= sizeof(rpc_fraghdr))
+        if (svsk->sk_datalen == 0)
                 return;
-        len = svsk->sk_tcplen - sizeof(rpc_fraghdr);
+        len = svsk->sk_datalen;
         npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
         for (i = 0; i < npages; i++) {
                 svsk->sk_pages[i] = rqstp->rq_pages[i];
@@ -907,9 +907,9 @@ static void svc_tcp_clear_pages(struct svc_sock *svsk)
 {
         unsigned int i, len, npages;
 
-        if (svsk->sk_tcplen <= sizeof(rpc_fraghdr))
+        if (svsk->sk_datalen == 0)
                 goto out;
-        len = svsk->sk_tcplen - sizeof(rpc_fraghdr);
+        len = svsk->sk_datalen;
         npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
         for (i = 0; i < npages; i++) {
                 BUG_ON(svsk->sk_pages[i] == NULL);
@@ -918,6 +918,7 @@ static void svc_tcp_clear_pages(struct svc_sock *svsk)
         }
 out:
         svsk->sk_tcplen = 0;
+        svsk->sk_datalen = 0;
 }
 
 /*
@@ -1066,8 +1067,10 @@ static int svc_tcp_recvfrom(struct svc_rqst *rqstp)
 
         /* Now receive data */
         len = svc_partial_recvfrom(rqstp, vec, pnum, want, base);
-        if (len >= 0)
+        if (len >= 0) {
                 svsk->sk_tcplen += len;
+                svsk->sk_datalen += len;
+        }
         if (len != want) {
                 svc_tcp_save_pages(svsk, rqstp);
                 if (len < 0 && len != -EAGAIN)
@@ -1100,6 +1103,7 @@ static int svc_tcp_recvfrom(struct svc_rqst *rqstp)
         /* Reset TCP read info */
         svsk->sk_reclen = 0;
         svsk->sk_tcplen = 0;
+        svsk->sk_datalen = 0;
         /* If we have more data, signal svc_xprt_enqueue() to try again */
         if (svc_recv_available(svsk) > sizeof(rpc_fraghdr))
                 set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
@@ -1296,6 +1300,7 @@ static void svc_tcp_init(struct svc_sock *svsk, struct svc_serv *serv)
 
                 svsk->sk_reclen = 0;
                 svsk->sk_tcplen = 0;
+                svsk->sk_datalen = 0;
                 memset(&svsk->sk_pages[0], 0, sizeof(svsk->sk_pages));
 
                 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;