libceph: kill last of ceph_msg_pos
The only remaining field in the ceph_msg_pos structure is
did_page_crc. In the new cursor model of things that flag (or
something like it) belongs in the cursor.
Define a new field "need_crc" in the cursor (which applies to all
types of data) and initialize it to true whenever a cursor is
initialized.
In write_partial_message_data(), the data CRC still will be computed
as before, but it will check the cursor->need_crc field to determine
whether it's needed. Any time the cursor is advanced to a new piece
of a data item, need_crc will be set, and this will cause the crc
for that entire piece to be accumulated into the data crc.
In write_partial_message_data() the intermediate crc value is now
held in a local variable so it doesn't have to be byte-swapped so
many times. In read_partial_msg_data() we do something similar
(but mainly for consistency there).
With that, the ceph_msg_pos structure can go away, and it no longer
needs to be passed as an argument to prepare_message_data().
This cleanup is related to:
http://tracker.ceph.com/issues/4428
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 19f9fff..eee7a87 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -1002,6 +1002,7 @@
/* BUG(); */
break;
}
+ data->cursor.need_crc = true;
}
/*
@@ -1069,12 +1070,12 @@
BUG();
break;
}
+ data->cursor.need_crc = new_piece;
return new_piece;
}
-static void prepare_message_data(struct ceph_msg *msg,
- struct ceph_msg_pos *msg_pos)
+static void prepare_message_data(struct ceph_msg *msg)
{
size_t data_len;
@@ -1086,8 +1087,6 @@
/* Initialize data cursor */
ceph_msg_data_cursor_init(&msg->data, data_len);
-
- msg_pos->did_page_crc = false;
}
/*
@@ -1186,7 +1185,7 @@
/* is there a data payload? */
con->out_msg->footer.data_crc = 0;
if (m->hdr.data_len) {
- prepare_message_data(con->out_msg, &con->out_msg_pos);
+ prepare_message_data(con->out_msg);
con->out_more = 1; /* data + footer will follow */
} else {
/* no, queue up footer too and be done */
@@ -1388,8 +1387,7 @@
size_t len, size_t sent)
{
struct ceph_msg *msg = con->out_msg;
- struct ceph_msg_pos *msg_pos = &con->out_msg_pos;
- bool need_crc = false;
+ bool need_crc;
BUG_ON(!msg);
BUG_ON(!sent);
@@ -1401,7 +1399,6 @@
return;
BUG_ON(sent != len);
- msg_pos->did_page_crc = false;
}
static void in_msg_pos_next(struct ceph_connection *con, size_t len,
@@ -1444,9 +1441,8 @@
{
struct ceph_msg *msg = con->out_msg;
struct ceph_msg_data_cursor *cursor = &msg->data.cursor;
- struct ceph_msg_pos *msg_pos = &con->out_msg_pos;
bool do_datacrc = !con->msgr->nocrc;
- int ret;
+ u32 crc;
dout("%s %p msg %p\n", __func__, con, msg);
@@ -1461,38 +1457,40 @@
* need to map the page. If we have no pages, they have
* been revoked, so use the zero page.
*/
+ crc = do_datacrc ? le32_to_cpu(msg->footer.data_crc) : 0;
while (cursor->resid) {
struct page *page;
size_t page_offset;
size_t length;
bool last_piece;
+ int ret;
page = ceph_msg_data_next(&msg->data, &page_offset, &length,
&last_piece);
- if (do_datacrc && !msg_pos->did_page_crc) {
- u32 crc = le32_to_cpu(msg->footer.data_crc);
+ if (do_datacrc && cursor->need_crc)
crc = ceph_crc32c_page(crc, page, page_offset, length);
- msg->footer.data_crc = cpu_to_le32(crc);
- msg_pos->did_page_crc = true;
- }
ret = ceph_tcp_sendpage(con->sock, page, page_offset,
length, last_piece);
- if (ret <= 0)
- goto out;
+ if (ret <= 0) {
+ if (do_datacrc)
+ msg->footer.data_crc = cpu_to_le32(crc);
+ return ret;
+ }
out_msg_pos_next(con, page, length, (size_t) ret);
}
dout("%s %p msg %p done\n", __func__, con, msg);
/* prepare and queue up footer, too */
- if (!do_datacrc)
+ if (do_datacrc)
+ msg->footer.data_crc = cpu_to_le32(crc);
+ else
msg->footer.flags |= CEPH_MSG_FOOTER_NOCRC;
con_out_kvec_reset(con);
prepare_write_message_footer(con);
- ret = 1;
-out:
- return ret;
+
+ return 1; /* must return > 0 to indicate success */
}
/*
@@ -2144,24 +2142,32 @@
struct page *page;
size_t page_offset;
size_t length;
+ u32 crc = 0;
int ret;
BUG_ON(!msg);
if (WARN_ON(!ceph_msg_has_data(msg)))
return -EIO;
+ if (do_datacrc)
+ crc = con->in_data_crc;
while (cursor->resid) {
page = ceph_msg_data_next(&msg->data, &page_offset, &length,
NULL);
ret = ceph_tcp_recvpage(con->sock, page, page_offset, length);
- if (ret <= 0)
+ if (ret <= 0) {
+ if (do_datacrc)
+ con->in_data_crc = crc;
+
return ret;
+ }
if (do_datacrc)
- con->in_data_crc = ceph_crc32c_page(con->in_data_crc,
- page, page_offset, ret);
+ crc = ceph_crc32c_page(crc, page, page_offset, ret);
in_msg_pos_next(con, length, ret);
}
+ if (do_datacrc)
+ con->in_data_crc = crc;
return 1; /* must return > 0 to indicate success */
}
@@ -2257,7 +2263,7 @@
/* prepare for data payload, if any */
if (data_len)
- prepare_message_data(con->in_msg, &con->in_msg_pos);
+ prepare_message_data(con->in_msg);
}
/* front */