libceph: some simple changes

Nothing too big here.
    - define the size of the buffer used for consuming ignored
      incoming data using a symbolic constant
    - simplify the condition determining whether to unmap the page
      in write_partial_msg_pages(): do it for crc but not if the
      page is the zero page

Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index e8f236e..1a22975 100644 (file)
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -38,6 +38,11 @@ static char tag_keepalive = CEPH_MSGR_TAG_KEEPALIVE;
 static struct lock_class_key socket_class;
 #endif
 
+/*
+ * When skipping (ignoring) a block of input we read it into a "skip
+ * buffer," which is this many bytes in size.
+ */
+#define SKIP_BUF_SIZE  1024
 
 static void queue_con(struct ceph_connection *con);
 static void con_work(struct work_struct *);
@@ -892,8 +897,7 @@ static int write_partial_msg_pages(struct ceph_connection *con)
                                      MSG_DONTWAIT | MSG_NOSIGNAL |
                                      MSG_MORE);
 
-               if (do_crc &&
-                   (msg->pages || msg->pagelist || msg->bio || in_trail))
+               if (do_crc && kaddr != zero_page_address)
                        kunmap(page);
 
                if (ret == -EAGAIN)
@@ -1982,8 +1986,9 @@ more:
                 *
                 * FIXME: there must be a better way to do this!
                 */
-               static char buf[1024];
-               int skip = min(1024, -con->in_base_pos);
+               static char buf[SKIP_BUF_SIZE];
+               int skip = min((int) sizeof (buf), -con->in_base_pos);
+
                dout("skipping %d / %d bytes\n", skip, -con->in_base_pos);
                ret = ceph_tcp_recvmsg(con->sock, buf, skip);
                if (ret <= 0)