libceph: encapsulate advancing msg page

In write_partial_msg_pages(), once all the data from a page has been
sent we advance to the next one.  Put the code that takes care of
this into its own function.

While modifying write_partial_msg_pages(), make its local variable
"in_trail" be Boolean, and use the local variable "msg" (which is
just the connection's current out_msg pointer) consistently.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 56448660883d5dad2df9969ec41599492a75d1d8..1b92e3b16c0d940858eaf98bc27f042bf22a5a2d 100644 (file)
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -891,6 +891,33 @@ static void iter_bio_next(struct bio **bio_iter, int *seg)
 }
 #endif
 
+static void out_msg_pos_next(struct ceph_connection *con, struct page *page,
+                       size_t len, size_t sent, bool in_trail)
+{
+       struct ceph_msg *msg = con->out_msg;
+
+       BUG_ON(!msg);
+       BUG_ON(!sent);
+
+       con->out_msg_pos.data_pos += sent;
+       con->out_msg_pos.page_pos += sent;
+       if (sent == len) {
+               con->out_msg_pos.page_pos = 0;
+               con->out_msg_pos.page++;
+               con->out_msg_pos.did_page_crc = false;
+               if (in_trail)
+                       list_move_tail(&page->lru,
+                                      &msg->trail->head);
+               else if (msg->pagelist)
+                       list_move_tail(&page->lru,
+                                      &msg->pagelist->head);
+#ifdef CONFIG_BLOCK
+               else if (msg->bio)
+                       iter_bio_next(&msg->bio_iter, &msg->bio_seg);
+#endif
+       }
+}
+
 /*
  * Write as much message data payload as we can.  If we finish, queue
  * up the footer.
@@ -906,11 +933,11 @@ static int write_partial_msg_pages(struct ceph_connection *con)
        bool do_datacrc = !con->msgr->nocrc;
        int ret;
        int total_max_write;
-       int in_trail = 0;
+       bool in_trail = false;
        size_t trail_len = (msg->trail ? msg->trail->length : 0);
 
        dout("write_partial_msg_pages %p msg %p page %d/%d offset %d\n",
-            con, con->out_msg, con->out_msg_pos.page, con->out_msg->nr_pages,
+            con, msg, con->out_msg_pos.page, msg->nr_pages,
             con->out_msg_pos.page_pos);
 
 #ifdef CONFIG_BLOCK
@@ -934,13 +961,12 @@ static int write_partial_msg_pages(struct ceph_connection *con)
 
                /* have we reached the trail part of the data? */
                if (con->out_msg_pos.data_pos >= data_len - trail_len) {
-                       in_trail = 1;
+                       in_trail = true;
 
                        total_max_write = data_len - con->out_msg_pos.data_pos;
 
                        page = list_first_entry(&msg->trail->head,
                                                struct page, lru);
-                       max_write = PAGE_SIZE;
                } else if (msg->pages) {
                        page = msg->pages[con->out_msg_pos.page];
                } else if (msg->pagelist) {
@@ -964,14 +990,14 @@ static int write_partial_msg_pages(struct ceph_connection *con)
                if (do_datacrc && !con->out_msg_pos.did_page_crc) {
                        void *base;
                        u32 crc;
-                       u32 tmpcrc = le32_to_cpu(con->out_msg->footer.data_crc);
+                       u32 tmpcrc = le32_to_cpu(msg->footer.data_crc);
                        char *kaddr;
 
                        kaddr = kmap(page);
                        BUG_ON(kaddr == NULL);
                        base = kaddr + con->out_msg_pos.page_pos + bio_offset;
                        crc = crc32c(tmpcrc, base, len);
-                       con->out_msg->footer.data_crc = cpu_to_le32(crc);
+                       msg->footer.data_crc = cpu_to_le32(crc);
                        con->out_msg_pos.did_page_crc = true;
                }
                ret = ceph_tcp_sendpage(con->sock, page,
@@ -984,30 +1010,14 @@ static int write_partial_msg_pages(struct ceph_connection *con)
                if (ret <= 0)
                        goto out;
 
-               con->out_msg_pos.data_pos += ret;
-               con->out_msg_pos.page_pos += ret;
-               if (ret == len) {
-                       con->out_msg_pos.page_pos = 0;
-                       con->out_msg_pos.page++;
-                       con->out_msg_pos.did_page_crc = false;
-                       if (in_trail)
-                               list_move_tail(&page->lru,
-                                              &msg->trail->head);
-                       else if (msg->pagelist)
-                               list_move_tail(&page->lru,
-                                              &msg->pagelist->head);
-#ifdef CONFIG_BLOCK
-                       else if (msg->bio)
-                               iter_bio_next(&msg->bio_iter, &msg->bio_seg);
-#endif
-               }
+               out_msg_pos_next(con, page, len, (size_t) ret, in_trail);
        }
 
        dout("write_partial_msg_pages %p msg %p done\n", con, msg);
 
        /* prepare and queue up footer, too */
        if (!do_datacrc)
-               con->out_msg->footer.flags |= CEPH_MSG_FOOTER_NOCRC;
+               msg->footer.flags |= CEPH_MSG_FOOTER_NOCRC;
        con_out_kvec_reset(con);
        prepare_write_message_footer(con);
        ret = 1;