libceph: use cursor for inbound data pages

The cursor code for a page array selects the right page, page
offset, and length to use for a ceph_tcp_recvpage() call, so
we can use it to replace a block in read_partial_message_pages().

This partially resolves:
    http://tracker.ceph.com/issues/4428

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This commit is contained in:
Alex Elder 2013-03-11 23:34:23 -05:00 committed by Sage Weil
parent 6518be47f9
commit 878efabd32

View file

@ -1441,8 +1441,10 @@ static void in_msg_pos_next(struct ceph_connection *con, size_t len,
msg_pos->data_pos += received;
msg_pos->page_pos += received;
if (ceph_msg_has_pages(msg))
(void) ceph_msg_data_advance(&msg->p, received);
#ifdef CONFIG_BLOCK
if (ceph_msg_has_bio(msg))
else if (ceph_msg_has_bio(msg))
(void) ceph_msg_data_advance(&msg->b, received);
#endif /* CONFIG_BLOCK */
if (received < len)
@ -2192,23 +2194,12 @@ static int read_partial_message_pages(struct ceph_connection *con,
unsigned int data_len, bool do_datacrc)
{
struct ceph_msg *msg = con->in_msg;
struct ceph_msg_pos *msg_pos = &con->in_msg_pos;
struct page **pages;
struct page *page;
size_t page_offset;
size_t length;
unsigned int left;
int ret;
/* (page) data */
pages = msg->p.pages;
BUG_ON(pages == NULL);
page = pages[msg_pos->page];
page_offset = msg_pos->page_pos;
BUG_ON(msg_pos->data_pos >= data_len);
left = data_len - msg_pos->data_pos;
BUG_ON(page_offset >= PAGE_SIZE);
length = min_t(unsigned int, PAGE_SIZE - page_offset, left);
page = ceph_msg_data_next(&msg->p, &page_offset, &length, NULL);
ret = ceph_tcp_recvpage(con->sock, page, page_offset, length);
if (ret <= 0)