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>

diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h
index 613cf42227aa35237c27e2b956100545ab36631f..62fd1b756e9914a63ea72ae21a401a7b14115161 100644 (file)
--- a/include/linux/sunrpc/svcsock.h
+++ b/include/linux/sunrpc/svcsock.h
@@ -26,8 +26,15 @@ struct svc_sock {
        void                    (*sk_owspace)(struct sock *);
 
        /* private TCP part */
-       __be32                  sk_reclen;      /* length of record */
-       u32                     sk_tcplen;      /* current read length */
+       /* On-the-wire fragment header: */
+       __be32                  sk_reclen;
+       /* As we receive a record, this includes the length received so
+        * far (including the fragment header): */
+       u32                     sk_tcplen;
+       /* Total length of the data (not including fragment headers)
+        * received so far in the fragments making up this rpc: */
+       u32                     sk_datalen;
+
        struct page *           sk_pages[RPCSVC_MAXPAGES];      /* received data */
 };
 

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 1db42b1ffe2861d504f3f738fc5bb690f78a880b..2b09e2306bfa1a23b9bd77684855c9d7f4992e10 100644 (file)
--- 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;