| Message ID | 513FD0CE.6000800@inktank.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index 07ace1d..1b003b4 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -1450,6 +1450,10 @@ static void in_msg_pos_next(struct ceph_connection *con, size_t len, msg_pos->data_pos += received; msg_pos->page_pos += received; +#ifdef CONFIG_BLOCK + if (ceph_msg_has_bio(msg)) + (void) ceph_msg_data_advance(&msg->b, received); +#endif /* CONFIG_BLOCK */ if (received < len) return;
Replace the use of the information in con->in_msg_pos for incoming bio data. The old in_msg_pos and the new cursor mechanism do basically the same thing, just slightly differently. The main functional difference is that in_msg_pos keeps track of the length of the complete bio list, and assumed it was fully consumed when that many bytes had been transferred. The cursor does not assume a length, it simply consumes all bytes in the bio list. Because the only user of bio data is the rbd client, and because the length of a bio list provided by rbd client always matches the number of bytes in the list, both ways of tracking length are equivalent. In addition, for in_msg_pos the initial bio vector is selected as the initial value of the bio->bi_idx, while the cursor assumes this is zero. Again, the rbd client always passes 0 as the initial index so the effect is the same. Other than that, they basically match: in_msg_pos cursor ---------- ------ bio_iter bio bio_seg vec_index page_pos page_offset The in_msg_pos field is initialized by a call to init_bio_iter(). The bio cursor is initialized by ceph_msg_data_cursor_init(). Both now happen in the same spot, in prepare_message_data(). The in_msg_pos field is advanced by a call to in_msg_pos_next(), which updates page_pos and calls iter_bio_next() to move to the next bio vector, or to the next bio in the list. The cursor is advanced by ceph_msg_data_advance(). That isn't currently happening so add a call to that in in_msg_pos_next(). Finally, the next piece of data to use for a read is determined by a bunch of lines in read_partial_message_bio(). Those can be replaced by an equivalent ceph_msg_data_bio_next() call. Since the read path has no need to know whether the next piece of a bio to use is the last, allow it to pass a null pointer as its last_piece argument to ceph_msg_data_bio_next(). This partially resolves: http://tracker.ceph.com/issues/4428 Signed-off-by: Alex Elder <elder@inktank.com> --- net/ceph/messenger.c | 17 ++++++----------- 1 file changed, 6 insertions(+), 11 deletions(-) @@ -2225,23 +2229,14 @@ static int read_partial_message_bio(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 bio_vec *bv; struct page *page; size_t page_offset; size_t length; - unsigned int left; int ret; BUG_ON(!msg); - BUG_ON(!msg->b.bio_iter); - bv = bio_iovec_idx(msg->b.bio_iter, msg->b.bio_seg); - page = bv->bv_page; - page_offset = bv->bv_offset + msg_pos->page_pos; - BUG_ON(msg_pos->data_pos >= data_len); - left = data_len - msg_pos->data_pos; - BUG_ON(msg_pos->page_pos >= bv->bv_len); - length = min_t(unsigned int, bv->bv_len - msg_pos->page_pos, left); + + page = ceph_msg_data_next(&msg->b, &page_offset, &length, NULL); ret = ceph_tcp_recvpage(con->sock, page, page_offset, length); if (ret <= 0)