SUNRPC: skb_read_bits is the same as xs_tcp_copy_data

Clean-up: eliminate xs_tcp_copy_data -- it's exactly the same logic as the
common routine skb_read_bits.  The UDP and TCP socket read code now share
the same routine for copying data into an xdr_buf.

Now that skb_read_bits() is exported, rename it to avoid confusing it with
a generic skb_* function.  As these functions are XDR-specific, they should
not have names that suggest they are of generic use.  Also rename
skb_read_and_csum_bits() to be consistent.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

3 files changed, 12 insertions, 27 deletions

diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
index 4d17846cd78a..a06aab278fe0 100644
--- a/include/linux/sunrpc/xdr.h
+++ b/include/linux/sunrpc/xdr.h
@@ -157,6 +157,7 @@ typedef struct {
 
 typedef size_t (*skb_read_actor_t)(skb_reader_t *desc, void *to, size_t len);
 
+size_t xdr_skb_read_bits(skb_reader_t *desc, void *to, size_t len);
 extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *);
 extern ssize_t xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,
                 skb_reader_t *, skb_read_actor_t);
diff --git a/net/sunrpc/socklib.c b/net/sunrpc/socklib.c
index 2635c543ba06..9c40d67c1ffb 100644
--- a/net/sunrpc/socklib.c
+++ b/net/sunrpc/socklib.c
@@ -16,7 +16,7 @@
 
 
 /**
- * skb_read_bits - copy some data bits from skb to internal buffer
+ * xdr_skb_read_bits - copy some data bits from skb to internal buffer
  * @desc: sk_buff copy helper
  * @to: copy destination
  * @len: number of bytes to copy
@@ -24,11 +24,11 @@
  * Possibly called several times to iterate over an sk_buff and copy
  * data out of it.
  */
-static size_t skb_read_bits(skb_reader_t *desc, void *to, size_t len)
+size_t xdr_skb_read_bits(skb_reader_t *desc, void *to, size_t len)
 {
         if (len > desc->count)
                 len = desc->count;
-        if (skb_copy_bits(desc->skb, desc->offset, to, len))
+        if (unlikely(skb_copy_bits(desc->skb, desc->offset, to, len)))
                 return 0;
         desc->count -= len;
         desc->offset += len;
@@ -36,14 +36,14 @@ static size_t skb_read_bits(skb_reader_t *desc, void *to, size_t len)
 }
 
 /**
- * skb_read_and_csum_bits - copy and checksum from skb to buffer
+ * xdr_skb_read_and_csum_bits - copy and checksum from skb to buffer
  * @desc: sk_buff copy helper
  * @to: copy destination
  * @len: number of bytes to copy
  *
  * Same as skb_read_bits, but calculate a checksum at the same time.
  */
-static size_t skb_read_and_csum_bits(skb_reader_t *desc, void *to, size_t len)
+static size_t xdr_skb_read_and_csum_bits(skb_reader_t *desc, void *to, size_t len)
 {
         unsigned int pos;
         __wsum csum2;
@@ -158,7 +158,7 @@ int csum_partial_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
                 goto no_checksum;
 
         desc.csum = csum_partial(skb->data, desc.offset, skb->csum);
-        if (xdr_partial_copy_from_skb(xdr, 0, &desc, skb_read_and_csum_bits) < 0)
+        if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_and_csum_bits) < 0)
                 return -1;
         if (desc.offset != skb->len) {
                 __wsum csum2;
@@ -173,7 +173,7 @@ int csum_partial_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
                 netdev_rx_csum_fault(skb->dev);
         return 0;
 no_checksum:
-        if (xdr_partial_copy_from_skb(xdr, 0, &desc, skb_read_bits) < 0)
+        if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
                 return -1;
         if (desc.count)
                 return -1;
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index a94aff42d08c..450c350a0c62 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -651,22 +651,6 @@ static void xs_udp_data_ready(struct sock *sk, int len)
         read_unlock(&sk->sk_callback_lock);
 }
 
-static inline size_t xs_tcp_copy_data(skb_reader_t *desc, void *p, size_t len)
-{
-        if (len > desc->count)
-                len = desc->count;
-        if (skb_copy_bits(desc->skb, desc->offset, p, len)) {
-                dprintk("RPC:      failed to copy %zu bytes from skb. %zu bytes remain\n",
-                                len, desc->count);
-                return 0;
-        }
-        desc->offset += len;
-        desc->count -= len;
-        dprintk("RPC:      copied %zu bytes from skb. %zu bytes remain\n",
-                        len, desc->count);
-        return len;
-}
-
 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, skb_reader_t *desc)
 {
         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
@@ -675,7 +659,7 @@ static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, skb_reader_t *desc
 
         p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
         len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
-        used = xs_tcp_copy_data(desc, p, len);
+        used = xdr_skb_read_bits(desc, p, len);
         transport->tcp_offset += used;
         if (used != len)
                 return;
@@ -721,7 +705,7 @@ static inline void xs_tcp_read_xid(struct sock_xprt *transport, skb_reader_t *de
         len = sizeof(transport->tcp_xid) - transport->tcp_offset;
         dprintk("RPC:      reading XID (%Zu bytes)\n", len);
         p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
-        used = xs_tcp_copy_data(desc, p, len);
+        used = xdr_skb_read_bits(desc, p, len);
         transport->tcp_offset += used;
         if (used != len)
                 return;
@@ -761,12 +745,12 @@ static inline void xs_tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc
                 memcpy(&my_desc, desc, sizeof(my_desc));
                 my_desc.count = len;
                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
-                                          &my_desc, xs_tcp_copy_data);
+                                          &my_desc, xdr_skb_read_bits);
                 desc->count -= r;
                 desc->offset += r;
         } else
                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
-                                          desc, xs_tcp_copy_data);
+                                          desc, xdr_skb_read_bits);
 
         if (r > 0) {
                 transport->tcp_copied += r;